Chapter 1 Engine Machinery

1.1 Engine main technical specifications and parameters

1.1.1 Main technical specifications

Engine model		HFC4GB2.3D	HFC4GB3.3D
Engine type		Inline four cylinders、double overhead camshafts、16 air valves、DVVT	Inline four cylinders、double overhead camshafts、16 air valves、DVVT
Working method		Four-stroke, homogeneous combustion	Four-stroke, homogeneous combustion
Emission level		China V	China V
Fuel type		Gasoline	Gasoline
Main Performance Parameters	Idling rotation speed（r/min ）	750±30	750±30
	Rated power(Kw)	85	88
	Rated rotation speed（ r/min ）	6000	6000
	Maximum torque(N.m)	150	155
	Maximum torque speed（r/min ）	3500-4500	3500-4500
	Total load minimum fuel consumption(g/kW· h)	245	245
	Displacement（ml）	1449	1590
	Compression ratio	10.5	10.5
	Cylinder diameter	75	75
	Stroke(mm)	84.8	90
	Crankshaft Rotating direction	Counterclockwise	Counterclockwise
	Ignition sequence	1-3-4-2	1-3-4-2
	Driving mode	Electrical power start	Electrical power start
	Lubrication method	Pressure and splash composite	Pressure and splash composite
	Cooling form	water cooling	water cooling
	Whole machine weight (kg)	90	90

1.1.2 Main parts specifications

Main parts parameter table

Parts name	Technical characteristics
Engine oil filter	Full flow rotary filter Thread specification M20×1.5-6H
Engine oil pump	Internal rotator type
Cooling water pump	Switch-type coolant pump
Thermostat	wax type Opening temperature:82℃ full open temperature:95℃
Generator	Internal regulator ac generator specification:14V 110A
spark plug	Iridium platinum alloy type
oil pressure guide rail	No oil return

1.1.3 Main inspection and adjustment parameters

Main inspection and adjustment parameters table

Valve clearance（mm）	intake valve 0.20±0.03 exhaust valve 0.30±0.03
Emission standard	China V
Engine oil temperature	≤135℃
Water temperature	≤110℃
sparking plug electrode gap	0.7～0.8mm

1.1.4 Bolt torque table

Name	Specification	Quantity	Tightening torque (N · m)
High strength bolts
Main bearing cover bolt	M9×1.25×74.5	10	（35±2）N·m+60°～64°
Connecting rod bolt	M6×0.75×33	8	5N·m→10N·m→13N·m+45°+45°
camshaft bearing cover bolt	M6×1×35	16	11±1
camshaft front bearing cover bolt	M8×1.25×30	3	20±1
Cylinder head bolt	M9×1.25×143.5	10	（24.5±2）N·m+180°～184°
crankshaft belt pulley bolt	M14×1.5×54	1	(50±2)N·m+(60±2)°
Flywheel bolt	M11×1.25×25	6	100±5
Exhaust valve timing regulator bolt	M10×41	1	100±5
Intake valve timing regulator bolt	M10×41	1	100±5
E-type bolt
Crankshaft rear oil seal bolt	M6×10 E8	6	7.6±0.6
rear lifting lug bolt	M8×20 E10	2	18.4±1.4
air inlet manifold bolt	M8×40 E10	5	18±1.0
oil pan bolt	M6×12 E8	16	11±1.0
sprocket chamber cover boltⅠ	M10×90 E14	2	39.5±3.0
sprocket chamber cover boltⅡ	M10×50 E14	2	39.5±3.0
sprocket chamber cover bolt Ⅲ	M6×30 E10	2	8.4±0.6
M6×20 E10-type bolt	M6×20 E10	6	8.4±0.6
M6×12 E10-type bolt	M6×12 E10	7	8.4±0.6
M6×45 E10-type bolt	M6×45 E10	2	8.4±0.6
M6×25 E10-type bolt	M6×25 E10	9	8.4±0.6
M6×12 E8-type bolt	M6×12 E8	1	8.4±0.6
cylinder head guard bolt	M6×27 E10	10	9±1.0
engine oil filter bracket bolt	M8×30 E12	2	20±1
blower water return steel tube bolt	M6×20 E8	2	7.6±0.6
oil pressure guide rail bolt	M8×35 E12	2	18.4±1.4
plug
Main oil duct plugⅠ	Inner hexagon M20	2	60±5
Main oil duct plugⅡ	Inner hexagon M12	1	35±5
WATER DRAIN SCREW PLUG	Inner hexagon M12	1	25±5
oil duct plug	Inner hexagon M10	1	20±2
VVT oil duct plug	M14×1.5×14	1	44±5
Oil drain plug	M14×1.5×14	1	39±5
other bolt
fixed track bolt assy.	M6×1×12	2	10±2
Movable track bolt assy.	M8×1.25×15	1	23.5±4.5
starter bolt	M8×55	2	24±3
engine oil pressure switch	R 1/8	1	10±2
spark plug	M14	4	25～30
exhaust manifold stud bolt	M8×1×12	5	12±2
Q1840816(exhaust manifold bracket bolt)	M8×16	2	20～25
CATALYTIC CONVERTER THERMAL INSULATION COVER NUT	M6×1	3	10±1
Crankshaft signal wheel bolt	M6	3	12.5±2.5
Water temperature sensor		1	20±4
hall sensor bolt	Inner hexagon M6×1×16	2	8~10
knock sensor bolt	Inner hexagon M8×1.25×30	1	20±4
exhaust manifold nut	M8	5	35±2
throttle valve self-tapping bolt	Inner hexagon spline M6×1×25	4	8~10
square head bolt	M10×1.25×90	1	47±5
idle gear bolt	M10×1.25×38	1	49±9
Oxygen sensor		2	35±5
Engine oil filter		1	Rotate three quarters of the circle after installation surface contact or 11±1N.m
idle gear assy.	M10×1.5	1	50±5

1.1.4 Maintenance limitation

Items		Standard value	Limit Value
Camshaft
Camshaft height (mm)	Air inlet	44.7054±0.1mm
Camshaft height (mm)	Exhaust	44.2836±0.1mm
Cylinder head and air valve
Cylinder head surface flatness (mm)		Below 0.03	0.1
Cylinder head total height (mm)		112.9～113.1
Air valve edge thickness (mm)	air inlet door		0.85
Air valve edge thickness (mm)	exhaust valve	1.85±0.15	1.35
Clearance between air stem and air valve guide pipe（mm）	Air inlet	0.020～0.036	0.10
Clearance between air stem and air valve guide pipe（mm）	Exhaust	0.030～0.045	0.15
Valve taper angle		45°～45.5°
Air valve total total length	air inlet door	89.61	89.11
Air valve total total length	exhaust valve	90.94	90.44
Free height of each valve spring（mm）		43.1	42.7
Valve spring loading/installing height（N）/（mm）		152×33.4
Valve spring loading/installing height（N）/（mm）		310×25.2
The first air ring sideshake（mm）		0.03～0.07	0.10
The second air ring sideshake（mm）		0.02～0.06	0.1
The first air ring open clearance（mm）		0.15～0.30	0.8
The second air ring open clearance（mm）		0.30～0.50	0.8
Combined oil ring open clearance（mm）		0.10～0.60	1.0
Piston pin external diameter （mm）		18.002～18.005
Connecting rod journal clearance（mm）		0.02～0.04	0.1
Big head side clearance of connecting rod		0.10～0.30	0.4
Crankshaft axial clearance（mm）		0.09～0.27
Crankshaft main journal diameter （mm）		46.004～46.029
Connecting rod shaft journal diameter（mm）		39.982～40.0
Crankshaft main journal diameter clearance（mm）		0.02～0.04
Cylinder head surface flatness (mm)		Below 0.03
Cylinder body total height (mm)		280
Cylindricity of cylinder body		0.007
Cylinder hole inner diameter (mm)		75.000～75.015
Clearance between piston and cylinders（mm）		0.02～0.04

1.2 Engine body

1.2.1 Common precautions

1. Precautions for discharging engine coolant

Discharge engine coolant after engine is cooling.

2. Precautions for disconnect fuel tube

1) before starting work, make sure there is no object in the working area that will cause combustion or spark.

2) Release the fuel pressure before disconnection and disassembly.

3) Disconnect the pipe and plug the opening to prevent fuel leakage.

3. Precautions for disassembly

1) When a dedicated service tool is required, please use a dedicated service tool. Please always pay attention to safety work and do not operate without following the instructions.

2) Take special care not to damage mating or sliding surfaces.

3) If necessary, block the opening of the engine system with tape or the like to prevent foreign objects from entering.

4) Organize the disassembled parts systematically for troubleshooting and reassembly.

5) The basic principle for loosening the bolts and nuts is to loosen the outermost part and then release its diagonal position. If you have specified a release order, please follow the order specified.

4. Precautions for inspection, maintenance and disassembly

Before repair or replacement, thoroughly inspect the parts and replace if necessary.

5. Precautions for assembly

1) Tighten the nuts and bolts with a torque wrench.

2) The basic principle of tightening the bolts and nuts is to tighten the middle with multi-step with the same degree of tightness, then tighten the internal and external diagonal position. If you have specified a release order, please follow the order specified.

3) Replace with new liner, oil seal or "O" ring.

4) Rinse thoroughly, clean and dry each part. Carefully check engine oil or engine coolant lines for any blockage.

5. Do not damage the sliding surface and matching surface. Thoroughly remove foreign materials such as fabric debris or dust. Before assembly, lubricate the sliding surface with oil.

6) After draining the engine coolant and refilling, release air from the line first.

7) After repair, start the engine and increase the engine speed Check the engine coolant, fuel, engine oil and intake and exhaust leaks.

6. Parts with the setting tightening angle

1) Final angle tightening of the following engine components:

①　cylinder head bolt

②　main bearing cover bolt

③　Connecting rod cover nut

2) Do not make the final torque according to the torque value.

3) The torque values for these parts apply to the pretensioning step.

4) Make sure thread and base surface are clean and oil is applied.

1.2.2 Precautions for sealant

1. Remove the sealant

After removing the retaining nut and bolt, separate the mating surfaces using a scraper and remove the old sealant.

note:

■ Be careful not to damage mating surfaces.

■ Insert the squeegee and tap it to slide it sideways as shown.

■Where the scraper is difficult to use, please use a rubber hammer to tap the parts for removal.

■ If you have to use tools such as a screwdriver, be careful not to damage the mating surfaces.

2. Sealant application steps

1) Use a squeegee to remove the old sealant attached to the pad application surface and mating surface.

note:

■ Thoroughly remove the old sealant from the grooves, fixing bolts and bolt holes in the sealant application surface.

2) Wipe clean sealant application surface and mating surface with unleaded gasoline, remove the attached water, grease and foreign matter.

3) Place the specified size of the sealant completely in the designated location.

■If there is a groove for the sealant, please put the sealant into the groove.

■ For bolt holes, please place the sealant inside the hole.Occasionally use outside the hole.

■Install the binding element within 5 minutes of applying the sealant

■If there is a stain on the sealant, remove it immediately.

■ Do not retighten the bolts or nuts after installation.

■ Thirty minutes after installation, refill with engine oil and engine coolant.

note:

■If there are any special instructions in this manual, please follow the instructions.

1.2.3 Preparation work

1、Maintenance tool

Special tools chart

Serial No.	tool	Outside view	Description
1	Flywheel stop		Fixed flywheel
2	Air valve spring compressor		Compression air valve spring
3	Oxygen sensor sleeve		Remove and install oxygen sensor
4	Oil pan remover		Remove oil pan
5	Air valve oil seal installing device		Install air valve oil seal
6	Camshaft oil seal installing device		Installing camshaft oil seal
7	Crankshaft front oil seal director		Guide when installing crankshaft front oil seal
8	Crankshaft front oil seal installer		Install crankshaft front oil seal
9	Crankshaft rear oil seal installing device		Install the crankshaft rear oil seal
10	Piston pin locating tool		Install and remove piston pin
11	guide sleeve		Coordinate with piston pin locating tool
12	Elastic belt tools		Install the elastic belt

2、Sealing and fastening adhesive for engine assembly

Sealing part	sealant
Crankshaft rear oil seal assembly-engine body	Dow Corning 3-0115 plane sealant
	Threebond 1217G
	Tonsan 1590
Oil pan-engine body-crankshaft rear oil seal assy.	Dow Corning 3-0115 plane sealant
	Threebond 1217G
	Tonsan 1590
Sprocket wheel cover-engine body-cylinder head	Dow Corning 3-0115 plane sealant
	Threebond 1217G
	Tonsan 1590
Bowl plug - cylinder head	Loctite 12086 Bowl plug sealant
Crankshaft signal wheel bolt	Loctite 262 thread tighten glue
Water temperature sensor	Tonsan 1243 thread sealing adhesive
engine oil pressure switch	Tonsan 1243 thread sealing adhesive

3、Lubricant oil

Type of lubricant oil
Engine oil type	Environment temperature	Quality grade
JAC G01 5W-30	-30℃～40℃	SM and above
JAC G02 5W-30	-30℃～40℃	SN and above

1.2.4 Engine belt

1、Check elastic belt

Warning:

■Be sure to operate after the engine has stalled.

1）Check whether or not they have aging、cracks、wear and oil stain. If necessary, please replace.

2）Check the belt deflection between the belt wheels at the center point of the belt。

■ It should be carried out when the engine is cold, or it has been shut down for 30min.

note:

■Elastic belt after the engine is running around 15 min, the tension will decay 30%-40% to reach stability at 330 ~ 330 N, if it continues to decay more than 10% after reaching stability , the skid appears, the belt has reached the limit, the belt should be replaced.

note:

■The belt groove should not be wrong with teeth during elastic belt installation, otherwise it will damage the belt;

Special auxiliary equipment should be used when elastic belt is installed, otherwise it is easy to cause belt damage.

9d7d3776 ■When installing the belt, make sure it meshes properly with the belt wheel groove。

■Do not let engine oil and engine coolant splash on the belt.

■Do not twine or bend the belt too much.

IMG_20170310_114001 IMG_20170310_113824

note:

■Make sure the belt meshes properly with the belt wheel groove。

■Make sure engine oil and engine coolant do not splash on the belt and each pulley groove.

1.2.5 Air inlet manifold and exhaust manifold

1、elements

1d79f00b 11064ed4

Air inlet manifold and exhaust manifold breakdown drawing

1-PCV valve connection hose 2-air inlet manifold bolt 3-charcoal canister solenoid valve connection hose 4-air inlet manifold seal ring 5-heat shield bolt 6-heat shield 7- exhaust manifold gasket 8-exhaust manifold nut 9-exhaust manifold 10-exhaust manifold bracket 11-exhaust manifold bracket bolt 12-electronic throttle valve 13-throttle valve seal ring 14-EGR steel tube 15-EGR valve 16-exhaust manifold

2 Air inlet manifold

1) disassembly

①　Disconnect the wire harness connector of the absolute pressure sensor

②　Disconnect hose connectors below:

■PCV valve connection hose

■Brake vacuum booster hose at the side of air inlet manifold

■Vacuum hose at the side of charcoal canister solenoid valve

③　Disassemble throttle valve self-tapping bolt,take down electronic throttle valve.

④　Remove the fixing bolts of air inlet manifold and intake manifold bracket.

■tightening torque: (22.5±2.5) N·m

⑤　Disassemble air inlet manifold bolt

■tightening torque: (18±1.0) N·m

⑥　Disassemble EGR valve、EGR steel tube

■tightening torque: (18±1.0) N·m

⑦　Take down Air inlet manifold assy.

2）Inspection after disassembly

Check whether or not the air inlet manifold has crack or other damage, the mating surface is deformed, and the air inlet manifold seal ring and throttle seal ring are damaged. If yes,Repair or replace please.

3) Installation

■Follow the opposite sequence of the demounting sequence.

note:

■Do not reuse the unusable parts

3、Exhaust manifold

1) disassembly

note:

■This operation is performed when the exhaust system is completely cooled。

①　Disconnect the wire plug of the front oxygen sensor. Remove the front oxygen sensor with a special tool if necessary.

■tightening torque: (35±5) N·m

note:

■Don't damage the oxygen sensor。

■Any oxygen sensor that falls from a place more than 0.5m to the hard ground cannot be used again. Please replace it。

②　1. Disassemble the fixing bolts of thermal insulation cover I on the exhaust manifold,take down the cover I.

■tightening torque: (10±1) N·m

③　2. Remove the exhaust manifold bracket bolts, and then take down exhaust manifold bracket.

■tightening torque: (22.5±2.5) N·m

④　Disassemble exhaust manifold nuts,and then take down exhaust manifold.

■tightening torque: (35±2) N·m

2）Inspection after disassembly

Check whether the exhaust manifold mating surface is deformed or not.

3) Installation

Follow the opposite sequence of the demounting sequence.

note:

■Do not reuse the unusable parts

■Do not over-tighten the oxygen sensor to avoid damaging the oxygen sensor。

1.2.6 Timing sprocket mechanism

1、element

Timing sprocket mechanism breakdown drawing

1-timing chain 2-Exhaust valve timing regulator 3-sprocket bolt 4-Moving rail bolt assembly 5-Moving rail assembly 6-Tensioner bolt 7-automatic tensioner 8-fixing rail assembly 9-fixing rail bolt assembly 10-air inlet valve timing regulator

2、Timing chain disassembly and assembly

1) disassembly

①　Remove the fixing bolt of water pump belt pulley.

■tightening torque: (8.4±0.6) N·m

Note: the elastic belt can be disassembled by the friction of the driving belt when elastic belt is not disassembled.

②　Remove the elastic belt and check whether the elastic belt is worn、 aged、cracked, etc. Replace the elastic belt if necessary.

③　Disassemble oil level gauge assembly。

■tightening torque: (8.4±0.6) N·m

④　Remove crankshaft pulley。

■tightening torque: （100±5）N·m+（90±2）°。

⑤　Remove the Generator。

⑥　Remove oil pan and cylinder head shield.

Note: The oil pump housing can only be removed after removing oil pan and cylinder head shield.

Remove oil pump housing.

⑦　Check the timing condition.

Note: check whether or not the timing points shown in the diagram meet the requirements.

⑧　Remove the fixing and moving rails of automatic tensioner and timing chain. And check for exceptions.

■tightening torque: automatic tensioner (10±1) N·m.

fixing rail:（10±2）N·m。

moving rail（23.5±4.5）N·m。

⑨　Remove exhaust valve timing regulator.

■Bolts’ tightening torque: (100±5) N·m

⑩　Remove air inlet valve timing regulator.

■Bolts’ tightening torque: (100±5) N·m

2）Assembly

Follow the reverse procedure above for disassembly. Pay attention to the timing points and installation torques during installation

Oil pump housing installation meets the following requirements:

a. When the oil pump housing is assembled, the glue coating surface should be clean, no oil, dirt, etc

And gelatinizing with corning 3-0115 surface sealant or equivalent products according to the following picture. The diameter of the rubber strip at point A is 22mm±0.5mm. The diameter of the rubber strip at point B is 1.5mm±0.5mm..

Oil pump housing gelatinizing introductions

b. The tightening sequence of oil pump housing bolts should follow the principle: pretightening first,

then fastening from the middle to both sides crosswise. It is required to tighten the bolts with larger diameters first and then tighten the bolts with smaller diameters

■Point 1-4 Bolts’ tightening torque: (39.5±3.0) N·m

■Point 5-15 Bolts’ tightening torque: (8.4±0.6) N·m

Oil pump housing bolts tightening sequence

1.2. Camshaft Assembly

1、element

Camshaft Assembly breakdown drawing

1-exhaust camshaft 2-mechanical tappet 3-air inlet camshaft 4-Valve timing regulator 5-Valve timing regulator bolt 6-OCV valve 7-fastening bolt

2、Disassembly and Assembly

1) disassembly

①　Disassemble ignition coil

②　Disassemble cylinder head guard assy.

③　Rotate crankshaft , let cylinder-1 piston stay at the stop point of compression.

④　Measure valve clearance.

气门间隙测量顺序

a. The valve clearance is measured at position A in the figure

b. If valve clearance does not meet the standards, it needs to be adjusted.

■It is important to note the measurement value as an important parameter to calculate the proper tappet label.

Standard valve clearance (State of cold machine)

Items	Specified state
Air inlet	（0.22±0.03）mm
Exhaust	（0.30±0.03）mm

⑥　Turn the crankshaft 360º clockwise , let cylinder-4 piston stay at the stop point of compression.

⑦　Measure the valve clearance at position B in the figure.

■It is important to note the measurement value as an important parameter to calculate the proper tapper label.

⑧　Remove engine front end belt, idler wheel and shock absorbing belt pulley.

⑨　Remove oil pan and engine oil suction filter.

⑩　Remove oil pump housing and timing chain.

11　Remove air valve timing regulator.

a. Fix the camshaft with a wrench.

b. Unscrew Intake valve timing regulator bolt.

■Bolts’ tightening torque: (100±5) N·m.

c. Take down air inlet and exhaust valve timing regulators.

12　Remove air inlet and exhaust camshaft.

a. Remove camshaft front bearing cover, in reverse numerical order as shown in the figure below.

b. Remove camshaft bearing cover, in reverse numerical order as shown in the figure below.

13　Measure the height of the camshaft

Air inlet:（44.7054±0.1）mm

Exhaust:（44.2836±0.1）mm

If the measured value is not within the standard value, replace the camshaft.

14　Remove the mechanical tappet in the unqualified valve clearance and adjust the valve clearance.

■Mark the removed tappet and the corresponding installation position to prevent forgetting the position of the column.

a. Measure the thickness of the removed mechanical tappet with a screw micrometer.

b. According to the measured valve clearance and the thickness of the old tappet,Calculate the thickness of the new tappet to make the valve clearance reach the specified range.

Items	specification
Air inlet	new tappet thickness=old tappet thickness+[ measured valve clearance-0.22mm]
Exhaust	new tappet thickness=old tappet thickness+[ measured valve clearance-0.30mm]

New tappet thickness table

※Example

ü Measured intake valve clearance＝0.26mm，marked as A。

ü Measured old tappet thickness＝2.79mm，marked as B。

ü Measured intake valve clearance+Measured old tappet thickness＝The clearance between the base circle of the camshaft and the top of the valve tappet，marked as C，C＝3.05mm。

ü C＝Intake valve clearance standard value+Ideal new tappet thickness。 So Ideal new tappet thickness＝3.05mm－0.22mm＝2.83mm。

■When calculating the thickness of the exhaust side tappet, the above equation should be replaced with exhaust valve clearance standard value.

c. The closest new tappet thickness ＝2.82mm or 2.84mm。 Select tappet 282 or tappet 284.

d. Select a new tappet with the closest thickness to the calculated value.

■The available tappets have 31 sizes, ranging from 2.70 to 3.30mm, increasing by 0.02mm.

■The identification number in the mechanical tappet indicates the thickness (e.g., 272 indicates the thickness value of 2.72mm).

Tappet thickness group table

Tappet number	Thickness /mm	Tappet number	Thickness /mm	Tappet number	Thickness /mm
270	2.70	292	2.92	314	3.14
272	2.72	294	2.94	316	3.16
274	2.74	296	2.96	318	3.18
276	2.76	298	2.98	320	3.20
278	2.78	300	3.00	322	3.22
280	2.80	302	3.02	324	3.24
282	2.82	304	3.04	326	3.26
284	2.84	306	3.06	328	3.28
286	2.86	308	3.08	330	3.30
288	2.88	310	3.10
290	2.90	312	3.12

2）Assembly

①　Install the new tappet selected after the calculation.

■Confirm the specific position of each new tappet selected after calculation (corresponding to the mounting hole), preferably mark the new tappet.

②　Install the camshaft and bearing cover and pre-tighten the bolts in the opposite order of disassembly.then tighten in this order.

■Engine oil should be applied to the camshaft journal and cam.

■Camshaft front bearing cover bolts(number 3) tightening torque: (20±1) N·m

■Camshaft bearing cover Bolts(number 16) tightening torque: (11±1) N·m

③　Measure again whether or not the valve clearance after adjustment meets the standard. If it is beyond the standard range, first check whether the tightening torque of bearing cover bolts meets the requirements or not.

■The bolt torque meets the requirement,Remove the mechanical tappet in the unqualified valve clearance and adjust the valve clearance.

■If the tightening torque of bolts does not meet the requirements, loosen all the bolts on this camshaft and tighten them to the specified torque in order. Measure valve clearance again, if there is any unqualified clearance,Remove the mechanical tappet in the unqualified valve clearance and adjust the valve clearance.

④　Install air valve timing regulator.

⑤　Install timing chain and oil pump housing.

⑥　Install engine oil suction filter and oil pan.

⑦　Install front-end power accessory and drive belt.

⑧　Install cylinder head guard、ignition coil.

■Check the sealing ring of cylinder head guard before installation to ensure no loss、damage、 scratch、crease and other defects, so as to ensure its sealing performance.

■The cylinder head guard bolts must be pre-tightened and fastened in the order shown in the figure,Tightening torque：（9±1)N·m。

1.2.8 Cylinder head

1. Maintenance on vehicle (the abnormal parts will be maintained and reinstalled back)

Check cylinder pressure:

①　Turn off the engine after thoroughly warming it up.

②　Release fuel pressure

■Remove the fuel pump fuse from the fuse box.

■Start the engine.

■After the engine is out, start the engine to idle two or three times to release the fuel pressure completely .

③　Remove ignition coils and spark plugs.

④　Install a spliced cylinder pressure gauge on the spark plug hole.

⑤　Step the accelerator pedal to the bottom and turn the ignition switch to "START" to start. When the meter pointer is stable, read the compression pressure and engine speed. Do the above steps to check the remaining cylinders

■Standard pressure: 1200 ± 100kPa.

■Minimum pressure：1100kPa。

■Allowable difference between cylinders：no more than100kPa。

note:

■Prevent foreign matter from entering the cylinder through the inlet。

■Always use a fully charged battery to get the required engine speed（200r/min）。

■If the compression pressure is below the minimum, check the valve clearance and other related parts (valve, valve seat, piston, piston ring, cylinder diameter, cylinder head and cylinder head gasket). After checking, measure the compression pressure again.

■If the compression pressure of some cylinders is low, add 10ml engine oil into the spark plug hole of the cylinder and re-check the cylinder pressure.

■If the cylinder pressure increases after the engine oil is added, the piston ring may be worn or damaged Check the piston ring and replace it if necessary.

■If the compression pressure is still low after the engine oil is added,the valve may fail. Check if the valve is damage. Replace damaged valve or valve seat.

■If the compression pressure of two adjacent cylinders is low and the pressure is still low after adding oil, the cylinder gasket may leak Please replace cylinder head gasket

⑥　After the inspection, please install the removed parts.

⑦　Start the engine and make sure it runs smoothly.

2、Disassembly and Assembly

1) disassembly

①　Release fuel pressure

②　Discharge engine coolant and oil. Refer to "replace engine coolant" and "replace engine oil".

note:

■Be sure to operate after the engine is cooling.

■Do not let engine oil and engine coolant splash on the belt.

③　Remove the following components and related parts:

■cylinder head guard。

■Elastic belt。 Refer to “Elastic belt”.

■Oil pan。

■Oil pump housing and timing mechanism。 Refer to “Timing sprocket mechanism”.

■Air inlet manifold。 Refer to “Air inlet manifold”.

■Exhaust manifold。 Refer to “Exhaust manifold”.

■Thermostat housing。 Refer to “Thermostat assy”.

■Engine oil dipstick guide pipe。

④　Unscrew cylinder head bolt.

■Disassemble in numerical order as shown below。

⑤　Remove cylinder head gasket

2）Inspection after disassembly

①　Check whether the cylinder head has cracks or other damage or not.

②　Check whether or not the waterways and oil channels between cylinder body and cylinder head are blocked, if any, please clean.

③　Check cylinder head flatness

Note: when this inspection is carried out, the flatness of cylinder block should also be checked. Refer to“cylinder block flatness”

a.Wipe the oil off the cylinder head and clear away sealant and carbon deposition.

note:

■Be careful not to let impurities fall into the cylinder head channel and oil channel。

b.Measure the flatness in six directions at multiple positions on the bottom surface of the cylinder head。

Standard value: 0.03mm below

Limit value: 0.10mm

Cylinder head height (new)：（113±0.1）mm

If the value is exceeded standard value, please grinding according to the specification. If the value is exceeded the limit value, please replace according to the specification.

note:

■The total grindable allowance of cylinder head and cylinder block mating surface is no more than 0.2mm。

3）Assembly

①　Install new cylinder head gasket

②　Install the cylinder head as follows:

a.Install the washer as shown in the picture on the right。

b.Apply appropriate amount of engine oil to the screw position and washer of cylinder head bolt。

c.Tighten bolts in numerical order as shown in the figure below until each bolt reaches torque (24.5 + 2) N·m。

d.Loosen the bolts completely。

e.Tighten bolts in the order again until each bolt reaches torque （24.5±2）N·m。

f.Paint the head of the cylinder head bolt and cylinder head (as shown in the right picture)。

g.According to tighten the sequence, tighten each bolt by extra 90 ° twist。

H.tighten each bolt 90 ° again, check whether the paint marks on bolt head aligns with the cylinder head。

note:

■If the bolt tightening Angle is less than 90 °, that means the fastening torque is not enough。

■If the bolt tightening Angle is more than 90 °, the bolt should be completely removed, and reinstall again

i.If the cylinder head bolts are replaced during maintenance,maintain according to the above steps a ~ h.

j.If the cylinder head bolts are not replaced during maintenance,maintain according to the order of a、b、e、f、g、h.

③　Follow the opposite sequence of the disassembly procedures to install.

4）Inspection after assembly

The following are the steps to check oil leakage, lubricant leakage and tail gas leakage:

①　Before starting the engine, please check the level of the engine cooling fluid and engine oil.

②　Turn the ignition switch to the "ON" position (when the engine is off) to check the connection for fuel leakage.

③　Start the engine. When accelerating the engine ,check the connection again for fuel leakage.

④　Run the engine to check for abnormal noise and vibration.

⑤　Thoroughly warm up the engine and check for leakage of fuel oil、exhaust gas or any oil/liquid (including engine oil and engine coolant).

⑥　After the engine has cooled, recheck the oil/liquid level(including engine oil and engine coolant). If necessary, refill to the specified level.

1.2.9 Valve

1、elements

Valve element diagram

1-Exhaust Valve Seat Ring 2-Exhaust Valve 3-air inlet valve 4-air inlet valve Seat Ring 5-valve oil seal 6-valve spring lower seat 7-valve spring 8-valve spring upper seat 9-valve lock clamp 10-valve guide pipe

2、Disassembly and assembly

1）Disassembly

①　Use spark plug sleeve to remove spark plug

②　remove the valve lock、valve spring and valve spring seat。

Use the valve spring compressor to compress the valve spring。

CAUTION:

■All the valve, valve spring and other components that being removed should be attached with the label, indicating the cylinder number and location.

■Store the parts securely.

③　Remove valve oil seal

④　Remove valve seat ring

⑤　Remove valve guide pipe

2）assembly

①　Install valve guide pipe

②　Install valve seat ring

③　Install valve oil seal

a.Install valve spring lower seat

b.Install new valve oil seal with special tools..

note:

■Valve oil seal cannot be reused

■The valve oil seal must be installed with the correct special tool

④　Install valve

⑤　Install valve spring

Note: install facing up with paint mark

⑥　Install air valve spring upper seat

⑦　Install valve lock clamp

■Install with valve spring compressor。

■After installation, tap the valve stem edge with a rubber hammer to check the installation。

⑧　Use spark plug sleeve to install spark plug

1.2.10 Cylinder block assembly

1、element

Cylinder block assembly breakdown drawing

1-main bearing cover bolt 2-main bearing cover 3-Main bearing lower bush 4-Main bearing upper bush 5-Cylinder block 6-Crankshaft rear oil seal assembly 7-Crankshaft rear oil seal bolt 8-thrust plate 9-flywheel bolt 10 flywheel 11-Crankshaft 12-Crankshaft signal wheel positioning sleeve 13-Crankshaft signal wheel 14-Crankshaft signal wheel bolt 15-crankshaft pulley 16-Crankshaft pulley baffle ring 17-Crankshaft pulley bolt

2、Disassembly and assembly

1）Disassembly

①　Remove the following engine accessories. Refer to the relevant chapters for details of the disassembly process.

■Engine air inlet manifold and engine exhaust manifold。

■Generator belt。

■Generator。

■Engine timing mechanism。

■Water pump。

■water pipe components。

■Generator fixing bracket、air condition compressor fixing bracket。

■ignition coil。

②　Fix the engine overall.

③　Discharge engine oil Refer to “Replace the Engine Oil”.

④　Remove flywheel assembly. Please use the special tool to fix the flywheel and then remove the fixing bolt.

note:

■Fixing bolts should be loosened in diagonal order。

⑤　Remove crankshaft rear bearing

note:

■Once the rear bearing of crankshaft is disassembled, it cannot be used again. Please replace it with a new one。

⑥　Remove the following system. Refer to the relevant chapters for details of the disassembly process.

■Cylinder head

■Oil pump housing

■Oil pan

⑦　Remove knock sensor

note:

■Do not drop or tap the sensor。

⑧　Remove rear oil seal bracket.

■The driver is inserted between the crankshaft and the rear oil seal housing for disassembly。

note:

■Once the rear oil seal is disassembled, it cannot be used again. Please replace it with a new one。

⑨　Remove piston and connecting rod assembly

Before removing piston and connecting rod assembly,Please check the clearance of the connecting rod head. Refer to “inspection after disassembly" below.

a. Rotate the crankshaft. Place the corresponding crankshaft of the connecting rod to be removed in the center of the bottom.

Note: For ease of reinstallation, a cylinder number can be printed on the side of the removed connecting rod head.

b.Remove connecting rod cover.

■Connecting rod bolts shall be used only once and shall not be reused.

c.Use a rubber hammer or similar tool to push the piston and connecting rod assembly out of the cylinder block.

note:

■Be careful not to let the connecting rod head damage the cylinder wall and crankshaft journal。

⑩　Remove the connecting rod bearing bush from the connecting rod and the connecting rod cover.

note:

■Identify installation locations and keep them in place without confusion.

11　Remove piston ring from piston.

Check the side clearance of the piston ring before removing it. Refer to “inspection after disassembly" below.

CAUTION:

■using piston ring expander。

12　Remove the piston from connecting rod as follows：

a.Insert the push rod (special tool) from the arrow mark side in the front

and install guide sleeve D.

B.place the piston front mark up

and install the piston and connecting rod assembly on the piston pin mounting base

(special tool)

c.Press the piston pin out with the press machine.

d.Separate the connecting rod and piston from the piston

and the connecting rod assembly

note:

After removing piston pin, put the piston, piston pin and connecting rod together in the same cylinder. Do not mix with the piston, piston pin and connecting rod of other cylinders.

13　Remove crankshaft main bearing cover

Before releasing the crankshaft bearing cover, measure the crankshaft axial clearance. Refer to “inspection after disassembly" below. Please loosen the main bearing cover bolts of crankshaft in numerical order as shown in the figure below

As shown in the picture on the right,When disassembling, the crankshaft bearing cover bolts can be used to shake the crankshaft bearing cover backwards and forwards to disassemble it.

14　Remove crankshaft

15　Remove crankshaft signal wheel

■Crankshaft signal wheel bolts are removed clockwise。

2）Inspection after disassembly

①　Crankshaft axial clearance

Use the driver to lever the crankshaft,record the reading of the dial indicator at the same time.

Standard : 0.09～0.27mm

If the measured value is not within the standard value, Please replace the thrust plate and remeasure it。 If it is still not within the standard range , please replace the crankshaft.

②　Connecting rod big head clearance

Measure the clearance between the connecting rod and the crankshaft arm with a feeler gauge.

Standard clearance: 0.10～0.30mm

Limit value: 0.4mm

If the measured value exceeds the limit, replace connecting rod and measure again. If the limit is still exceeded, replace the crankshaft.

③　piston ring side clearance

Measure the clearances between piston ring and piston ring grooves with a feeler gauge.

Standard:

First groove：0.03～0.07mm

Second groove：0.02～0.06mm

limit:

First groove：0.10mm

Second groove：0.10mm

If the measured value exceeds the limit, replace piston ring and measure again. If the limit is still exceeded, replace the piston ring.

④　piston ring opening clearance

Make sure the cylinder inner diameter is within the specified range Refer to “Cylinder cylindricity”.

Lubricate the piston and piston ring with engine oil and insert the piston ring until the piston reaches the middle of the cylinder,and use feeler gauge to Measure piston ring opening clearance.

Standard:

First groove：0.15～0.30mm

Second groove：0.30～0.50mm

Combined oil ring: 0.10～0.60mm

limit:

First groove：0.8mm

Second groove：0.8mm

Combined oil ring: 1.0mm

If the measured value exceeds the limit, replace piston ring and measure again. If the limit is still exceeded, replace the cylinder block.

⑤　Cylinder block flatness

Clean the liner on the cylinder block surface, as well as engine oil、 scale、carbon or other contaminants.

note:

■Be careful not to let gasket chips fall into engine oil or engine coolant.

The flatness of cylinder block is measured with a ruler and a feeler gauge in six different directions.

Standard value: 0.03mm below

Limit value: 0.1mm

If the limit is exceeded, replace the cylinder block.

⑥　Connecting rod journal clearance

note: use plastic wire gauge for measurement.

a.Remove all engine oil from the connecting rod journal and the connecting rod bearing bush.

b.Place the plastic wire gauge on the connecting rod journal and cut it into the same length as the width of the bearing bush. plastic wire gaugemust be at the center of connecting rod journal and parallel to its axis.

c.Gently place the connecting rod cover in its position and tighten the bolts to the specified torque.

d.Remove the bolts and slowly remove the connecting rod cover.

e.Measure the extruded part of the plastic wire gauge at the widest point using a ruler printed on the plastic wire gauge bag.

Standard value:0.02~0.04mm

Limit value: 0.10mm

f.Remove the plastic clearance gauge completely after measurement.

If the clearance is greater than the limit, replace the connecting rod bearing bush. Replace the crankshaft if necessary.

⑦　Crankshaft main journal diameter clearance

a. Clean the engine oil of crankshaft journal and inner surface of bearing bush.

b. Install bearing bush.

c. Cut the length of the plastic wire gauge to

match the width of the bearing bush Then place it on the journal along the axis of the journal.

d. Lightly install the crankshaft bearing cover and tighten the bolts to the specified torque.

e. Remove the bolts and gently remove the crankshaft bearing cover.

f. Measure the extruded part of the plastic wire gauge at the widest point using a ruler printed on the plastic wire gauge bag.

Standard value:0.02~0.04mm

Limit value: 0.10mm

If the clearance is greater than the limit, replace the main bearing bush. Replace the crankshaft if necessary.

3）assembly

①　Preassemble crankshaft signal wheel

■Ensure no engine oil in the threaded hole of crankshaft signal wheel when assembling.

■Crankshaft signal wheel screw must be coated with Loctite 262 thread fastener or equivalent product before installation

■Crankshaft signal wheel bolts are tightened counterclockwise as shown in the figure below

②　Blow engine coolant and engine oil out of cylinder block, cylinder diameter and crankshaft box ,remove foreign matter.

note:

■Use goggles to protect your eyes.

③　Install main bearing bush upper bearing bush

note:

■elect the bearing bush according to the identification mark or color code of the crankshaft (refer to the assembly table of the main bearing bush). If it cannot be identified, the crankshaft diameter should be measured and the corresponding bearing bush should be selected to match it.

There are grouping marks on the crankshaft, marking a total of 10 digits. The first 5 digits correspond to the 1st to 5th main journals respectively. The 6th bit printing: "B", indicating the end of main journal grouping and the beginning of connecting rod journal grouping; The 7th to 10th bits correspond to the 1st to 4th connecting rod journals respectively.

connecting rod bearing bush project(start and stop model)

1d925888

connecting rod bearing bush project(non-start-stop model)

c72c97f7 DSCN0552

The exhaust rear end of the lower end face of cylinder block is marked with the dimension mark of the main shaft hole, corresponding to the dimension of the 1st to 5th main shaft hole respectively.

Main bearing bush shall be selected according to the following table

Main bearing bush installation table

Main bearing hole grouping mark position	Crankshaft grouping marks
Main bearing hole grouping mark position	1	2	3	4	5
0(up／down）	Black／Black	Black／yellow	Black／red	Black／white	Black／purple
1(up／down）	Yellow／Black	Yellow／Yellow	Yellow／red	Yellow／white	Yellow／purple
2(up／down）	Red／Black	Red／Yellow	Red／Red	Red／white	Red／purple

■When installing, aim the protrusion of the bearing bush at the cutting of the cylinder block and the main bearing cover.

■Make sure the engine oil hole on the cylinder block is aligned with the oil hole on the corresponding bearing bush

④　Install crankshaft to cylinder block. When rotating the crankshaft by hand, please check whether the rotation is flexible or not.

■Before installing crankshaft, appropriate amount of engine oil should be applied to the inner part of upper bearing bush.

⑤　Install thrust plate

Install oiled thrust plate in installation groove side of the main bearing seat(fourth), 100% measure and ensure that the crankshaft axial clearance is 0.09 ~ 0.27 mm, when installing two thrust surfaces ensure that the flat side joint fourth position, with groove side facing the cylinder holes.

⑥　Install main bearing cover

■The main bearing cover can be identified by identification marks

■Starting from the front end (timing belt side), install the main bearing cover in order of number

■The arrow must point to the front

⑦　Tighten the main bearing cover bolts as shown in the figure below

a.Apply engine oil to the thread and fixed surfaces of the main bearing cover bolts

b.Tighten the main bearing cover bolts in several steps

■Bolts’ tightening torque: (35±2) N·m+60°～64°。

■After installing the main bearing cover bolts, make sure the crankshaft can be rotated flexibly by hand

■Check crankshaft axial clearance Refer to “Crankshaft axial clearance”

⑧　Preassemble piston connecting rod assembly

■When installing the piston pin, make sure the top of the piston marked forward and the connecting rod marked forward are the same.

a.Measure the following lengths（As shown in diagram below）

A：Dimensions from piston boss to piston boss outside

B：Dimensions from piston boss to piston boss inside

C：Piston pin length

D：Connecting rod small end thickness

b.The measured value is putted into the following formula：

L=[（A-C）-(B-D)]/2

c.Insert the push rod (special tool) into the piston pin and install guide sleeve A (special tool)。

d.When piston and connecting rod are installed, the front marks should be on the same side。

e.Apply engine oil to the outer ring of the piston pin。

f.Starting with guide sleeve A, press guide sleeve A ,piston pin and push rod into the front marking side of the piston successively。

g.Screw guide sleeve B into guide sleeve A, and the gap between the two sleeves is 3mm plus the L value calculated in step 2。

h.Install the piston and the connecting rod on the piston pin mounting base in a downward marked state in front of the piston。

C.install the piston pin with the press machine.

note:

■If the pressure distribution load exceeds the specified limit, the piston pin and the piston assembly and the connecting rod shall be replaced, or both shall be replaced

Standard value: 108±54N·m

⑨　Install piston ring.

■Be careful not to damage the piston when installing piston rings

■Be careful not to damage the piston ring because of overextending

a. Install oil ring

ü Install the oil liner ring into the piston ring groove Then install the oil ring body

When installing the ring body, put one end of the ring body into the groove by hand, and then press the rest into the position.

note:

■Do not use piston ring expander to install ring body, otherwise it may lead to wiper blade fracture

ü After installing the combined oil ring body, check whether it can move smoothly in both directions

b. Install1st and 2nd air ring

ü Install the air ring with the piston ring expander. The identification mark on the air ring should be toward the top of the piston

c. Piston ring opening direction

⑩　Install the connecting rod bearing bush on the connecting rod and the connecting rod cover

■Apply engine oil to the surface of the connecting rod bearing bush before installing it。

■Connecting rod bearing bush shall be installed with special tool to ensure the installation position: as shown in the figure below, the difference between A and B length is less than 0.5mm。

未标题-1

11　Install piston connecting rod assembly on crankshaft

■Rotate crankshaft journal corresponding to the connecting rod to be removed in the center of the bottom.

■Apply engine oil to cylinder diameter, piston and crankshaft journal。

■Install the connecting rod to the corresponding cylinder hole according to the mark on the connecting rod

■Make sure the mark on the top of the piston is pointing forward

■Using the piston guide tool, put the piston connecting rod assembly into the guide tool from the cylinder fire surface and press the piston into the cylinder block with the rubber rod.

CAUTION:

■Be careful not to let the connecting rod head damage the cylinder wall and crankshaft journal。

12　Install connecting rod cover

13　Tighten connecting rod bolts, according to the “5N·m→10N·m→13N·m+45+45°” approach to tighten alternately.

note:

■Before installing the bolts, apply engine oil to the threaded parts and seating surfaces.

■After installing the piston connecting rod assembly, rotate the crankshaft to check whether the crankshaft can rotate flexibly or not.

14　

Install the rear oil seal bracket with the crankshaft rear oil seal on the cylinder block Use special tools to press the rear oil seal on the rear oil seal bracket

■When installing crankshaft rear oil seal bracket, ensure that the coating surface is clean, no oil, dirt, etc., apply Dow corning sealant 3-0115 or equivalent product on the surface of the cylinder block back-end as shown below, the sealant can also be applied on the corresponding position of crankshaft rear oil seal bracket. Rubber strip diameter（2±0.5）mm。 Apply lubricating oil to the rear oil seal lip and crankshaft joint, Be careful not to scratch the oil seal when installing.

■Bolts’ tightening torque: (7.6±0.6) N·m

Crankshaft rear oil seal glue line

15　Install knock sensor

■Bolts’ tightening torque: (20±4) N·m

Note: make sure there is no foreign matter between cylinder block and knock sensor.

16　Install flywheel

■Bolts’ tightening torque: (100±5) N·m

note:

■Follow the principle of pre - tightening first and then symmetrical cross - tightening。

1.3 Engine lubricating system

1.3、Installation precautions

Sealant application steps:

1、Use a squeegee to remove the old sealant attached to the pad application surface and mating surface.

note:

■ Thoroughly remove the old sealant from the grooves, fixing bolts and bolt holes in the sealant application surface.

2、 Wipe clean sealant application surface and mating surface, remove the attached water, grease and foreign matter.

3、 Place the sealant in the designated location.

1）Install the binding element within 5 minutes of applying the sealant

2）If there is a stain on the sealant, remove it immediately.

3） Do not retighten the bolts or nuts after installation.

4） Thirty minutes after installation, refill with engine oil and engine coolant.

1.3.2 Engine oil

1. Inspection

1）Engine oil level

Note: before starting the engine, stop the car horizontally and check the engine oil level. If the engine has started, turn off the engine and wait for 10min to check again.

①　Pull out engine oil dipstick and wipe it clean.

②　Insert the engine oil dipstick and make sure the oil level of the engine is within the range as shown in the figure.

③　Please adjust it if it is out of the range.

2）Engine oil appearance

①　Check engine oil for white turbidity or serious contamination.

②　If engine oil is turbid or contaminated, it is likely to be contaminated by engine coolant. repair or replace damaged parts.

3）Engine oil leakage

Check for oil leakage around the following areas:

■Oil pan

■Oil pan oil drain bolt

■Engine oil pressure switch

■Engine oil filter

■The mating surface of cylinder block and cylinder head

■Front and rear crankshaft oil seal

■The mating surface of cylinder block and oil pump

■The mating surface of cylinder head guard and cylinder head

■Front and rear camshaft oil seal

4）oil pressure checking

note:

■The engine oil is very hot, be careful not to get scalded.

■Check the oil pressure after parking.

①　Check the oil level

②　Lift the vehicle, disconnect the wire connector of engine oil pressure switch and remove the switch.

③　Install oil pressure gauges and hoses

④　Start the engine and warm it to normal working temperature.

⑤　Check oil pressure during engine running with no-load

Note: when the engine oil temperature is low, the oil pressure increases.

■If there is any obvious difference, please check the oil pipeline and oil pump for leakage.

⑥　After inspection, install the pressure switch as follows:

a.Remove old sealant that is attached to pressure switches and engines

b.Use sealant as required and tighten pressure switch

■Please use the specified sealant：Tonsan 1243 thread sealing adhesive

■Bolts’ tightening torque: (10±2) N·m

c.After warming up the engine, make sure there is no oil leakage when the engine is running normally.

2、Replace the Engine Oil

①　Start engine and preheat until the engine coolant temperature reaches (80 ~ 90 ℃).

②　Remove engine oil filler cover from the cylinder head guard.

③　Remove the drain screw plug from the oil pan to drain the oil The oil discharge time shall not be less than 15min.

note:

■The engine oil is very hot, be careful not to get scalded.

④　Use special spanner to disassemble the oil filter;

⑤　Clean filter installing surface on oil filter bracket.

⑥　Replace the new oil filter:Apply a small amount of oil to the o-ring of the oil filter. When the o-ring of the oil filter touches the flange of the oil filter holder, use a special wrench to twist 3/4 circles or equal to (11 + 1) N·m.

⑦　Install oil duct screw plug on the oil pan.

■Bolts’ tightening torque: (39±5) N·m

⑧　Inject the oil from the oil inlet on the cylinder cover guard, about 4L.

⑨　After starting the engine without load and running for (2-3) min, check the interface between filter and bracket to ensure no oil leakage.

⑩　Turn off the engine and wait for 10min to check whether the oil level is between the upper and lower scale. If oil is insufficient, please add.

■Measurement method of the engine oil: when measuring, Cars should be parked horizontally, after the oil level of oil is stable, pull out oil dipstick, wipe engine oil with a clean cloth, then insert it in oil pan to measure the oil level The engine oil level shall be kept in the middle and upper part of two scale lines of the oil dipstick. The height of oil level should also be checked before leaving the vehicle and every driving (300 ~ 500)km. If the oil quantity is insufficient, it should be added timely.

1.3.3 Engine Oil Filter

1、Disassembly and Assembly

1) disassembly

Use special tools to disassemble the oil filter;

note:

■Use original jianghuai oil filter

■The engine oil is very hot, be careful not to get scalded.

■When disassembling, prepare a cloth to dry the leaking or splattering engine oil.

■Do not let the engine oil stick to the drive belt.

■Thoroughly dry the engine oil spilled on the engine and the car

2)MOUNTING

①　Clean filter installing surface on oil filter bracket.

②　Replace the new oil filter:Apply a small amount of oil to the o-ring of the oil filter. When the o-ring of the oil filter touches the flange of the oil filter holder, use a special wrench to twist 3/4 circles or equal to (11 + 1) N·m.

note:

■The oil filter must be tightened with the filter wrench

■If the filter is tightened by hand, oil may leak due to insufficient tightening torque.

2、Inspection after assembly

1）After starting the engine without load and running for (2-3) min, then check the interface between filter and bracket ,engine oil should not leak.

Turn off the engine and wait for 10min,then check whether or not the oil level is between the upper and lower scale. If the oil is insufficient, please add.

1.3.4 Oil pan and Oil pump

1. Disassembly

1）Discharge engine oil.

2）Remove oil pan.

a.Loosen the retaining bolt in the order of both sides first and middle.

b.As shown in the figure, tap in a special tool between the oil pan and the cylinder block.

c.Tap the side of the special tool and move the tool along the oil pan/cylinder block sealing face, then remove the oil pan.

Note:

■ Be careful not to damage mating surfaces.

3）Remove engine oil suction filter

■Bolts’ tightening torque: (8.4±0.6) N·m

4）Remove oil pump housing.

2、Inspection after disassembly

1）Engine oil suction filter

■Clean the attachment clearly.

2）Oil pump housing

■ Check whether all the oil holes on the oil pump are clogged, and clean the holes if it is necessary .

■Check the oil pump housing for cracks or other damage If yes, please replace.

3. Assembly

1）Install oil pump housing.

■Ensure the glue coating surface be clean, no oil, dirt, etc

■Apply Dow corning 3-0115 surface sealant or equivalent products. Refer to “oil pump housing installation”

2）Install crankshaft front oil seal

■Place the special tool at the front of the crankshaft and apply engine oil to its periphery.

■Apply the engine oil to the sealing lip, then push the oil seal along the guide sleeve by hand until it touches the front oil seal housing. Using special tool , tap it in place.

3）Install the relief valve assembly

4）Install engine oil suction filter.

5）Install oil pan.

■Before installing the oil pan, make sure the cylinder block、sprocket chamber cover、the bottom end face of the oil seal bracket are clean、 no machine oil、no dirt, etc.

■Remove the remaining sealing glue of the previous process at the three-point joint surface of the sprocket chamber cover、oil seal bracket and cylinder block, and uniformly apply the new sealing glue on the joint surface. The diameter of the rubber strip is 4mm. 2222

■Ensure the glue coating surface be clean, no oil, no dirt, etc

■Apply Dow corning 3-0115 surface sealant or equivalent products along the center of glue tank on flange face of oil pan

■The control method for the amount of glue applied is: the diameter of the glue strip is combined with its weight, and the diameter is: the diameter of glue strip in zone A is 3mm±0.5mm. The diameter of glue strip in zone B is 4mm±0.5mm, as shown in the figure below.

■glue strip weight：The glue weight of each oil pan is controlled between 13g to15g.

■Tightening method of oil pan bolts: follow the tightening from the middle to both sides, as shown in the following sequence.

■First pre-tighten, then retighten to the specified torque：（11±1）N·m。

6）Install oil drain bolts on oil pan

■Bolts’ tightening torque: (39±5) N·m

7）Add engine oil, about 4L.

note:

■Wait at least 30 minutes after installing the oil pan before adding the engine oil

4、Inspection after assembly

1）Start the engine and make sure there is no oil leakage

2）Turn off the engine and wait for 10min,then check whether or not the oil level is between the upper and lower scale. If the oil is insufficient, please add.

1.4 Engine cooling system

1.4.1 Cooling circuit

1、Cooling principle map

Cooling principle map

1.4.2 Engine Coolant

1. Inspection

1）Liquid level inspection

■ When the engine is cooled down, check if the engine coolant level in a range from MIN to MAX.

■If necessary, adjust the engine coolant level.

■If the coolant level is too low, check for leakage.

2）Leakage inspection

Apply pressure on the cooling system to 120kPa using the radiator cap leak detector to check and confirm that the pressure has not decreased If the pressure drops, check hoses、radiators and water pump for leaks. If no external leakage is found, check the heating core、cylinder block and cylinder cover.

note:

■Do not remove the radiator cap when the engine is hot.Otherwise, high-pressure engine coolant escaping from the radiator can cause serious burns.

■ Exceeding test pressure may damage the heat sink.

■When engine coolant decreases, add engine coolant to the radiator. If parts are found damaged, please repair or replace them.

3）Coolant quality inspection

Check the quality of antifreeze liquid, if there is turbidity、deterioration、odor、foaming and other phenomena, it is necessary to replace the coolant and clean the water channel.

2、Engine coolant replacement

note:

■To avoid burns, do not replace the coolant when the engine temperature is high

■Cover the radiator cap with a thick cloth and unscrew it carefully. Release the pressure inside the radiator and then completely unscrew the cover.

■Be careful not to spill engine coolant on the drive belt.

1）Discharge the engine coolant

①　Open the radiator drain plug at the bottom of the radiator and open the radiator cap.

②　Check the engine coolant for iron rust and other impurities or discoloration

2）Refill the engine coolant

①　Install the removed tank and radiator drain plug.

note:

■ Be sure to clean the drain plug and install a new o-ring.

②　Confirm that each hose clamp is firmly tightened.

③　Disconnect the warm air outlet hose. Raise the hose as high as possible

④　Fill the radiator and reservoir with coolant to the specified level.Slowly add the engine coolant so that the air in the system is gradually discharged.

note:

■Use the original JAC engine coolant Refer to “Recommended oil/liquid and Lubricants”

■Reconnect and continue filling engine coolant when engine coolant overflows blower water outlet hose

⑤　Install the radiator cover.

⑥　Warm to open the thermostat.

Make sure the thermostat is open by touching the radiator down pipe to feel if there is any warm water coming out.

note:

■Check the engine water temperature indicator to avoid overheating

⑦　Turn off the engine to reduce the temperature.

⑧　The engine coolant in the tank was added to the MIN to MAX range.

⑨　install the radiator cap and Repeat ③～⑧more than twice with until the engine coolant level no longer drops.

⑩　Run engine check cooling system for leaks.

3）Flush the cooling system

note:

■Be sure to clean the drain plug and install a new o-ring.

①　Disconnect the blower water outlet hose. Raise the hose as high as possible

②　Add engine coolant to the radiator and reservoir and install the radiator cap.

③　Reconnect and continue filling engine coolant when engine coolant overflows warm air outlet hose

④　Run the engine to preheat to normal working temperature.

⑤　Speed up the engine speed several times under no-load condition.

⑥　Turn off the engine and wait for cooling.

⑦　Drain water from the system. Refer to “Drain engine coolant”

⑧　Repeat steps ①～⑦ until the radiator begins to drain clear water.

1.4.3 Water pump

1、Disassembly and Assembly

note:

■When removing the pump,Be careful not to spill engine coolant on the drive belt.

■The water pump cannot disintegrate and should be replaced as a whole.

■After installing the pump, connect the hose and fix it with a clamp, then use the radiator cap leak detector to check for leakage.

1) disassembly

①　Drain engine coolant from the radiator. Refer to “Engine coolant replacement”

②　Loosen the fixing bolt of water pump belt pulley.

■tightening torque: (8.4±0.6) N·m

③　Remove elastic belt。

④　Remove the fixing bolt of water pump

■tightening torque: (8.4±0.6) N·m

2）Inspection after disassembly

■Check the water pump assembly for serious corrosion, water seal leakage or corrosion

■Check for excessive end clearance resulting in poor work.

■Check whether the pump bearing is stuck or has other damage. Please replace it if necessary.

■The water pump is an on-off pump, which does not work under the condition of power-on, and works under the condition of power-off.

3）Assembly

①　Clean water pump sealing surface

②　Install water pump

■Tighten each fixing bolt evenly and alternately.

③　Install water pump belt pulley

④　Install the elastic belt

⑤　Add the engine coolant

2、Inspection after assembly

■use the radiator cap leak detector to check for leakage.

■Start and warm up the engine. Visually check engine coolant for leakage.

1.4.4 Thermostat assy.

1、Disassembly and Assembly

1) disassembly

①　Drain engine coolant from the radiator water drain plug.. Refer to “Engine coolant replacement”

note:

■Be sure to operate after the engine is cooling.

■Do not let engine coolant splash on the belt.

②　Disconnect the radiator inlet and outlet pipes and short circle pipes on the side of the thermostat housing

③　Disconnect the wire harness connector of the coolant temperature sensor and the water temperature attention switch, and the fixing bolt of the fixing bracket of the front and rear oxygen sensor wire harness connector and remove them.

④　Remove the fixing bolt of the warm air water return pipe and remove the pipe.

⑤　Remove the fixing bolts of thermostat upper cover and remove the thermostat.

2）Inspection after disassembly

①　Thermostat

■Check the throttle valve opening at normal room temperature

The opening temperature of the thermostat：82°C（open start），95°C（full open）。

Maximum lift of valve rod：≥8mm

The closing temperature of the thermostat：>77°C

If the measured value exceeds the specified range, please replace the thermostat.

②　thermostat upper cover and thermostat housing

Check for cracks or other damage.

3）Assembly

Please note the following items and install in the reverse order of disassembly.

①　Be careful not to spill engine coolant on the engine Use a cloth to dry the engine coolant.

②　Replace the "O" ring of water inlet pipe with the new "O" ring, and then apply the coolant to the "O" ring so that they can be easily embedded in the water pump and thermostat housing.

note:

■Do not apply engine oil or other oil substances to the “O” ring.

■The water pipe behind the thermostat housing must be securely installed.

③　When installing a thermostat, keep its jump valve in the highest position.

④　If the water temperature sensor is to be reused, the specified sealant should be applied to its threads.

■specified sealant：Tonsan 1243 thread sealant

2、Inspection after assembly

■use the radiator cap leak detector to check for leakage. Refer to "Leakage Inspection"

■Start and warm up the engine. Visually check engine coolant for leakage.

1.4.5 Water pipe assy.

1. Disassembly

①　Drain engine coolant from water drain plug at the bottom of the radiator Refer to “Engine coolant replacement”

note:

■Be sure to operate after the engine is cooling.

②　Remove the radiator upper and lower water hose

③　Remove warm water hose and short circle hose.

④　Remove the inlet pipe fixing bolt and remove the water inlet pipe from the back end of the water pump.

note:

■Before disassembling, disassemble the battery negative terminal first

2. Assembly

Please note the following items and install in the reverse order of disassembly.

1）Firmly insert each hose Install the clamp ring, and the clamp ring will not clamp the boss of the pipe

2）Replace the "O" ring of water inlet pipe with the new "O" ring, and then apply the coolant to the "O" ring so that they can be easily embedded in the water pump and thermostat housing.

note:

■Do not apply engine oil or other oil substances to the “O” ring.

■The water pipe behind the thermostat housing and water pump must be securely installed.

3、Inspection after assembly

1）use the radiator cap leak detector to check for leakage.

2）Start and warm up the engine. Visually check engine coolant for leakage.

1.5 Engine emission control system

1.5.1 Fuel evaporation system

1、System description

Fuel evaporation system map

Fuel evaporation system theory map

The fuel evaporation system is used to reduce hydrocarbon emissions from the fuel system into the atmosphere. Use activated carbon in EVAP tanks to reduce hydrocarbon emissions. When the engine is not running or refueling to the tank, the vapors from the sealed tank are guided into the EVAP tank with activated carbon and stored there. When the engine is running, the fuel vapor in the EVAP carbon tank is carried into the intake manifold through the clean line. EVAP Carbon canister solenoid valve is controlled by ECM. When the engine is working, the steam flow controlled by the EVAP carbon tank solenoid valve is adjusted proportionally to the increase of air flow.

2、Component inspection

1）EVAP Carbon canister solenoid valve

Steam by-pass line opening of EVAP Carbon canister solenoid valve controls airflow rate. According to the signal sent by ECM, the EVAP carbon canister solenoid valve repeatedly opens/closes (ON/OFF), and the valve opening changes to achieve the best engine control. The optimal value stored in the ECM is determined by the different states of the engine. When the engine is running, the airflow rate of fuel steam from EVAP carbon canister is adjusted with the change of air flow.

①　Component Description

The EVAP carbon canister solenoid valve uses the ON/OFF duty ratio to control the flow rate of fuel steam out of the EVAP carbon canister. The EVAP carbon canister solenoid valve is driven by an open /OFF (ON/OFF) duty ratio signal sent from the ECM. The longer width of the (ON) pulse, the more fuel vapor will flow through the valve.

②　disassembly

a.

Disconnect the vacuum hose of the EVAP carbon canister solenoid valve.

b. Disconnect the wire harness connector of the EVAP carbon canister solenoid valve.

_DSC2507

c.Take down the EVAP carbon canister solenoid valve from air inlet manifold bracket.

3) Oil filler cover

a vacuum relief valve is installed on oil filler cover When the pressure in the fuel tank is high (more fuel vapor), the vacuum relief valve is closed to prevent the fuel vapor from escaping into the atmosphere. When the pressure in the fuel tank is low (negative pressure), the vacuum relief valve opens to allow the outside air to enter the fuel tank.

1.5.2 Crankshaft box force ventilation system

1、System instruction

Crankshaft box force ventilation system map

1-Air filter 2-air inlet hose 3-throttle valve body 4-purification can 5-PCV valve

6-PCV valve connecting hose 7-air inlet manifold 8-injector

The crankcase forced ventilation system is designed to send the cylinder air back to air inlet manifold

The crankcase forced ventilation valve(PCV) is designed to send the cylinder air back to air inlet manifold When the throttle of the engine is partially opened, the air inlet manifold is sucked into crankshaft box air through the PCV valve. Normally, the PCV valve has enough air volume to fully inhale the crankshaft box air and a small amount of ventilation air. ventilation air is drawn into the crankshaft box from the air inlet pipe In this process, the air passes through a hose that connects air inlet pipe to the rocker chamber cover. When the throttle of the engine is fully opened, The vacuum of the air inlet manifold is not sufficient to open the PCV valve and inhale the crankshaft box air. The air will flow in the opposite direction through the connecting hose. The PCV valve cannot meet the requirements in a vehicle with a particularly severe gas leakage. because in any case a portion of the gas will pass through the hose to the air inlet pipe.

2、Component inspection

PCV（Crankshaft box force ventilation ）valve inspection as follow：

1) Working principle:

PCV valve working principle table


Engine working conditions	out of action	Engine working conditions	Idle or decelerate
PCV valve	does not work	PCV valve	Fully open
vacuum degree change	limit	vacuum degree change	Slightly

Engine working conditions	Working normally	Engine working conditions	Acceleration and high speed abnormal
PCV valve	Working normally	PCV valve	Working slowly
vacuum degree change	large amplitude	vacuum degree change	very large

2. Disassembly

①　Disconnect the PCV valve connecting hose to the cylinder cover guard.

②　Remove the PCV valve from the cylinder cover guard side.

Inspection after disassembly

①　PCV valve

A normal working valve makes a hissing noise when airflow passes. When your finger is at the entrance of the valve, you immediately feel a strong vacuum pressure.

②　PCV valve connection hose

a.Check hoses and hose connections for leaks

b.Disconnect all hoses and clean with compressed air. If the plug in the hose cannot be removed, replace it.

4) Assembly

①　Install PCV valve

■Tightening torque is about 4N, cannot be too big

②　Install hose

Chapter 3 Engine Electronic Control System

3.1 Attentions

3.1.1 Common maintenance precautions

All the failures in electronic control system sensors, actuators, control circuits, ECM and other components will have some impact on the operation of the engine. Because the ECM has fault self-diagnostic capabilities, the computer tester can be connected to the ECM for troubleshooting to identify the cause of the fault in the electronic control system by reading the fault code or data flow.

In order to improve the reliability of the engine electronic control system work, most of the system components are structurally designed to be sealed, indecomposable, damaged and can not be repaired. The main task of electronic control system maintenance is to find faulty parts of the system, and replace the faulty parts.

When servicing the electronic control system, the following precautions must be taken to avoid damage to the ECM or control components.

1. Only the use of automotive diagnostic tools can be taken to check the electronic control system (such as digital multimeter, automotive oscilloscope and car diagnostic, etc.).

2. Please use genuine JAC parts in maintenance operations, otherwise it can not guarantee the normal work of the system.

3. Only unleaded gasoline can be used during maintenance and use.

4. Please follow the standard maintenance diagnosis process for maintenance operations.

5. It is prohibited to operate the disassembly work on the system in the maintenance process.

6. You must be very careful to pick and place electronic components (electronic control module, sensors, etc.) and do not let it fall.

7. Establish awareness of environmental protection, and effectively handle the waste generated during the maintenance process.

8. Do not remove or plug in the ECM's harness plug when the ignition switch is on, to prevent the inductive components in the electronic control system from generating induced voltage during the power-off or power-on instant, causing damage to the ECM.

9. The ECM harness connector should be securely connected, or the ECM may be damaged.

10. When dismantling the battery or use an external battery across the start, you must first turn off the ignition switch, and then you can make the folded or cross-connect operation. Pay special attention to the battery that can not be connected reversed.

11. When the battery connector is not tightened, never start the engine. Also do not remove the battery cable while the engine is running. Otherwise it will make the engine charging voltage too large, damaging the electronic control system components.

12. When turning the engine to check the cylinder compression pressure, please cut off the injector power or unplug all the injector harness connector to prevent the fuel injected into the exhaust without examination, resulting in three-way catalytic converter damage.

13 . When the ignition system is inspected , the spark detection shall be carried out only if necessary , and the time shall be as short as possible , otherwise a large amount of unburned gasoline will enter the exhaust pipe and damage the three-way catalyst converter.

14. Do not allow the ECU temperature to exceed 80 ° C while performing thermal condition simulations of faults and other maintenance operations that may raise the temperature.

15. Removal of tubing and replacement of fuel filters should be carried out by professional maintenance personnel in well-ventilated areas.

16. Prohibit the use of piercing wire skin to detect the input and output components of the electrical signal.

3.1.2 Diagnostic tool

■Tool name: electrospray system diagnostic instrument

Functions: read/clear the fault code of the electrical spraying system, observe the data flow, test the action of parts, etc.

■Tool name: digital multimeter

Function: check the voltage, current, resistance and other characteristic parameters in the electrospray system.

3.1.3 Engine OBD System Cautions

The Electronic Control Module (ECM) comes with an on-board diagnostic system that lights up when there is malfunction caused by the aging exhaust system.

■ Before performing any repair or inspection work, please turn the ignition switch OFF and disconnect the battery negative terminal. Open or short circuits in associated switches, sensors, and solenoid valves will cause the fault indicator to light up.

■ After work, be sure to connect and reliably lock the connector. Loose (unlocked) connectors may open the circuit and cause the fault indicator to light. (Make sure no dirt such as water, grease and other dirt on the connector, and the connector pins are without bending, fracture, etc.)

■ After work, be sure to arrange and fix the harnesses correctly. If the bracket interferes with the harness, it may cause a short circuit , causing the fault lamp to light up.

■After work, make sure the rubber hose is connected If the rubber hose is not connected properly, the failure indicator light may be turned on due to the failure of EVAP system and fuel injection system.

■ Before returning the vehicle to the customer, be sure to clear the useless fault information in the ECM (repair has been completed).

■ Be sure to use a 12V battery as the power source.

■Do not disconnect the battery while the engine is running.

■ Before connecting or disconnecting the ECM harness connector, turn the ignition switch to the "OFF" position and disconnect the negative battery terminal. Or it may damage the ECM because the battery is still energizing the ECM even when the ignition switch is turned "OFF".

■ Before removing the parts, turn the ignition switch OFF and disconnect the negative battery terminal.

■ Do not disassemble the ECM.

■If a battery cable is disconnected, the memory is returned to the ECM initial value. ECM will begin to control itself based on the initial value When the battery port is disconnected, the running of the engine will change slightly. But that does not mean there is a failure. Don't change parts for minor changes

■ When connecting the ECM harness connector, push the lever to the bottom to lock the ECM securely.

■ When inserting the pin connector into the ECU or removing it from the ECU, be careful not to damage the pin port (bend or broken). When connecting the pin connector, make sure the ECM pin port is not bent or broken.

■ Securely connect the ECM harness connector. Poor connection can cause very high (ripple) voltage on the coil and capacitor, causing damage to the ECU.

■ Keep the engine electronic control system components and harness dry.

■ Even a small leak in the air intake system can cause serious malfunctions, so do not easily replace the air intake pressure sensor.

■ Do not shake the camshaft position sensor (phase) or crankshaft position sensor(location).

■ When measuring the ECM with a circuit tester, do not contact the two gauges together the probe is inadvertently touched, resulting in a short circuit and damage to the ECM power transistor.

■When measuring the input/output voltage, do not use the ECM grounding port. Otherwise, the transistor of ECM may be damaged. Grounding except the ECM port should be used;

■Do not use the fuel pump when there is no fuel in the fuel pipe;

■Tighten the fuel hose clamp to the specified torque

■ Do not step on the accelerator pedal during start-up.

■ Do not immediately increase the engine speed after starting.

■Do not accelerate before closing the engine

3.2 Structure Principle and Maintenance of the Engine Control System

3.2.1 System description

1-carbon canister 2-Carbon canister solenoid valve 3-Electronic throttle valve assembly 4-intake pressure temperature sensor 5-oil atomizer 6-camshaft position sensor 7-ignition coil 8-Front oxygen sensor 9-three-way catalyst 10-rear oxygen sensor 11-engine coolant temperature sensor 12-crankshaft position sensor 13- fuel filter 14-electric fuel pump 15-fuel tank 16-diagnose interface 17-ECM

The picture shows the control system diagram, such as sensor location and physical discrepancies, please prevail in kind.

3.2.2 Electronic control system components

1.fuel injection system

the timing and width of the fuel injection are controlled to provide the best air/fuel mix ratio for the engine, which is suitable for changing engine operating conditions. Oil injectors are installed at the inlet of each cylinder Fuel is pumped out of the fuel tank by the fuel pump and distributed to each injector Under normal circumstances, it will spray fuel to each cylinder every two revolutions of the crankshaft. he working order of each cylinder is 1-3-4-2.

2.Ignition control system

The ignition system consists of ignition switch, ECU and ignition coil,

The sensors related to ignition control include crankshaft position sensor, inlet temperature and pressure sensor,

water temperature sensor, throttle position sensor and so on.

The main function of the ignition system is to control working of ignition coil, thus to control ignition advance angle of engine, which is one of the main control functions of the engine electronic control system. According to the engine speed, throttle opening, coolant temperature, inlet temperature pressure, knock sensor and other operating conditions measured by various sensors, ECU calculates and selects the ignition angle which is most suitable for the current working condition, which make it have high fuel economy and power performance, reduce emission pollution and prevent deflagration.

The ignition advance angle is determined and controlled by ECU according to the signals of various sensors.

Closing angle is the angle that the crankshaft or camshaft turns on during the current conduction of the ignition coil. Closing angle control also known as ignition coil electrification time control. For inductive energy storage type ignition system, the induction voltage produced by the ignition coil depends on the current of the primary coil passing through the coil at the moment of breaking. The higher the current value of the primary coil, the higher the inductive voltage of the ignition coil. Because of the inductive effect of the coil, under the condition of constant supply voltage, the current flowing through the coil increases exponentially at the beginning of the primary coil conduction, and it takes a certain time before the saturation current can be reached. When the closing angle remains constant, the time of primary current conduction will decrease with the increase of engine speed. In order to meet the requirements of ignition voltage and ignition energy of gasoline engine, the closing angle of ignition system is automatically controlled by ECM according to engine speed. When engine speed increases, the closing angle will be increased appropriately to ensure that the primary coil has enough conduction time, so that the current of the primary coil can reach or approach the saturation current at the moment of disconnection, rising the inductive voltage. On the contrary, when engine speed is reduced, ECM will properly reduce the closing angle, so as to prevent the primary coil from overheating and excessive power consumption due to the excessive conduction time of the primary coil current.

3.Air intake control system

Air intake system consists of air filter, throttle valve, intake manifold and related pipe.

Air intake control system is to achieve idle control, variable valve control, electronic throttle control, turbocharger control and other tasks through the control of air intake,

so as to improve the stability of engine idling operation, or improve engine power, reduce fuel consumption and emission pollution.

Idle speed control: the electronic control system has the function of automatic control of engine idling speed. Through engine working temperature, load and other factors measured by various sensors, to determine the optimal idle speed. And through electronic throttle, the intake amount of idle speed when automatically controlled idling, achieve the purpose of controlling idling speed. So that the engine has stable idle speed under various conditions, to prevent idle speed instability or stall, and as far as possible to reduce idle fuel consumption and emissions pollution.

Electronic throttle control: in the engine with electronic throttle valve, ECU measures operating condition of accelerator pedal according to various sensors, also calculates and confirms optimum opening degree of throttle valve according to engine speed, vehicle speed and other factors, control opening degree of throttle valve by electronic throttle valve actuator, and ensure the best fuel economy and improve safety and comfort. In addition, the electronic control system of gasoline engine can realize traction control and cruise control through electronic throttle valve.

Variable valve control: in engine with variable valve, ECU calculates and confirms the optimal phase of valve distribution according to operating conditions measured by various sensors. Through timing control of solenoid valve and other actuators, change opening and closing time of intake and exhaust valve, so that the phase of engine valve and valve overlap angle change with the change of engine speed and load, and keep the best at all times. Thus, the engine has good fuel economy, power performance and running stability at any speed and load, and reduces emission pollution.

4.Emission control system

The post-treatment of exhaust in three-way catalytic converters is an effective way to reduce the concentration of harmful substances in the exhaust gas. Ternary catalytic converters can reduce hydrocarbon (HC), carbon monoxide (CO) and nitrogen oxides (NOx) by 98% or more, and convert them into water (H2O), carbon dioxide (CO2) and nitrogen (N2). However, such high efficiency can only be achieved within a narrow range of the engine's excess air coefficientl =1，land the goal of closed-loop control is to ensure that the mixture concentration is within this range.l The closed-loop control system can only act with oxygen sensors The oxygen sensor at the side of the three-element catalytic converter monitors the oxygen content in the exhaust gas，The dilute mixture（l>1）generates a sensor voltage of about 100mV，The thick mixture（l<1）generates about 900mV sensor voltage。 whenl=1，The sensor voltage has a jump。l Closed-loop control responds to input signals（l>1=Mixed gas is too thinl<1=Mixed gas is too thick)Modify the control variable to produce a correction factor as a multiplier to modify the duration of the injection.

5.Crankshaft ventilation system

The function of fuel vapor recovery device is to recover the gasoline vapor from the gasoline tank of vehicle to engine intake pipe,

so that it can burn into the engine cylinder with the fresh mixture, and prevent gasoline vapor from being discharged into the atmosphere to pollute the environment.

The fuel vapor recovery unit consists of activated carbon canister, solenoid valve, one-way valve and corresponding steam pipe and vacuum hose.

3.2.3 Vehicle diagnostic system

1.Instruction

On-board Diagnostic system (OBD) is a diagnosis system integrated in engine control system which can monitor the fault parts and the main function state of engine which affect the exhaust gas emission. It has the function of identifying, storing and displaying fault information through the self-diagnostic malfunction indicator light (MIL).

2.function introduction

The main functions of the diagnostic system are monitoring functions, memory fault codes and warning functions, fail-safe functions

and data output functions.

（1）Monitoring function

The target of the diagnosis system monitoring is the various sensors in the engine electronic control system, actuator

and the control process of the electronic control system. The fault self-diagnosis system continuously monitors the signal of the electronic control system during the running of the vehicle, when a signal exceeds the preset range value, and the phenomenon does not disappear in a certain period of time. The fault self-diagnosis system determines that the corresponding circuit or component of the signal has failed.

（2）Store fault code and warning function. Once the fault self-diagnosis system detects a fault in the electronic control system, it immediately lights the fault warning light above the dashboard to remind the driver to promptly send the vehicle to the repair shop for inspection and maintenance, so as to avoid any further damage.

The fault self-diagnosis system also detects that the fault is stored

in the memory of the ECM as a fault code. During maintenance, the inspector can read out the fault code stored in the ECM by using a certain method to provide an accurate basis for finding the fault location.

（3）Failure protection function According to the different monitoring object, the fault self-diagnosis system will take different failure protection measures when finding fault.

（4）Data storage output function. The cells that store data in ECU are ROM and RAM, respectively, memory ROM stored in the program is based on accurate calculation and a large number of experimental data, the inherent program in the engine work, constantly with the acquisition of the signals of each sensor to compare and calculate, to achieve the control of the engine.

In the automotive electronic control system circuit has a dedicated diagnostic socket, as long as the car ECM decoder and this diagnostic socket connection,

you can access the automotive ECM storage unit, read out the stored fault code.

In addition, the fault self-diagnosis system can also output the data flow reflecting the working condition of the automobile electronic control system by diagnosing the outlet outward.

3.Fault light description and control strategy

1）Engine fault indicator light (MIL)：instructions required for emissions-related components or system failures, MIL is generally a light that can be displayed on the dashboard in compliance with regulatory standards.

2 The activation of the Mil led follows the following principles:

①　Ignition switch is in the "ON" state (non-start), MIL continues to light.

②　3 seconds after the engine starts, if there is no fault request in the fault memory to turn on the MIL, the MIL goes off.

③　There is a fault in the memory required to light the MIL request, or outside the ECM has a MIL request, MIL are lit.

④　When there is a flashing MIL request outside the ECM, or there is a blinking MIL request due to a fire or there is a fault request in the memory that flashes MIL, the MIL flashes at 1Hz.

4. Troubleshooting steps

1) For vehicles with OBD function, troubleshooting is generally followed by the following steps:

OBD Troubleshooting Steps Table

	1. Connect the diagnostic test equipment to the diagnostic connector and switch on the diagnostic test equipment.
	2. Connect the ignition switch.
	3. Read fault related information (fault code, frozen frame, etc.); check workshop manual to confirm fault parts and types; making maintenance plan according to fault related information and experience.
	4. Troubleshooting.
	5. To clear the fault memory, the proper operation of the vehicle and the operation mode must meet the conditions of the corresponding fault diagnosis; Read the fault information to confirm that the fault has been excluded.

2）Fault diagnosis common detection and diagnostic equipment

Compared with the mechanical system, the automobile electronic control system has a fundamentally different overhaul mode. It is necessary to rely on the electronic equipment and use the information of the self-diagnosis system to diagnose the fault. The common equipment for overhaul of electronic control system includes automobile computer tester and digital multimeter.

Connect the data cable of the computer detector to the diagnostic outlet on the car to connect with the automotive ECM, accessing to the ECM memory of the fault diagnosis data, including fault code, data flow and so on, so as to understand the auto fault diagnosis system monitoring results and the work of the electronic control system, to provide a basis for quick troubleshooting. In addition, it can carry out the action test and so on.

（1）Read and Clear fault codes

By connecting the car's computer detector with the fault diagnosis seat on the car, it is easy to read

the fault code stored in the ECM. The car's computer diagnostic device displays both the fault and its meaning on the screen By reading the fault codes, maintenance personnel can find out the short circuit, open circuit and other faults of most sensors and their control circuits in the automotive electronic control system.

After troubleshooting, the computer tester can send instructions to the car electronic control system to eliminate ECM stored fault code to turn off the the fault warning light.

（2）Read data stream

The car computer tester is connected with the electronic control system to read the running status of the ECM

and the instantaneous data of various input and output electric signals (such as the signal of each sensor, the calculation result of the ECM, the control mode, The control signal issued by each actuator, etc.). Maintenance personnel can judge whether the system is working normally according to the changes of various data or compare the values of various signals with the standard values under specific working conditions so as to accurately determine the type and location of the fault.

（3）Action test

The motion test is to issue a work instruction to the ECM of the automotive electronic control system through the computer tester to drive

or stop the work of some actuators to detect the working condition of the actuator and find the faulty actuator or control circuit.

3.2.4 Engine fault diagnosis

1、Engine control system troubleshooting overview

If the engine electronic control system components (sensors, ECM, injector, etc.) failure, oil supply disrupts or it can't provide the correct fuel quantity for engine different working conditions, will produce the following situations:

a.The engine is difficult to start or cannot start at all

b.Engine idling unstable

c.Poor driving performance

In case of any of the above situations, routine testing including basic engine inspection (ignition system failure, correct engine adjustment, etc.) shall be conducted first. Then the components of the engine electronic control system are checked by a fault diagnosis instrument

MT62.1 Common fault code list of ECU control system

No.	Fault code	Fault code information
1	P 0012	Air inletVCPCamshaft phase error is large
2	P 0015	ExhaustVCPCamshaft phase error is large
3	P 0016	IntakeVCPcamshaft tooth learning deviation exceed range
4	P 0017	ExhaustVCPcamshaft tooth learning deviation exceed range
5	P 0026	intakeVCPhydraulic pressure control valve vised
6	P 0027	ExhaustVCPhydraulic pressure control valve vised
7	P 0031	Front oxygen sensor heater short circuit to low voltage
8	P 0032	Front oxygen sensor heater short circuit to high voltage
9	P 0037	Rear oxygen sensor heater short circuit to low voltage
10	P 0038	Rear oxygen sensor heater short circuit to high voltage
11	P 0068	Electronic throttle valve air flow fault
12	P 0075	intakeVCPhydraulic pressure control valve coil low voltage or open circuit
13	P 0076	intakeVCPhydraulic pressure control valve coil low voltage
14	P 0077	intakeVCPhydraulic pressure control valve coil high voltage
15	P 0078	exhaustVCPhydraulic pressure control valve coil low voltage or open circuit
16	P 0079	exhaustVCPhydraulic pressure control valve coil low voltage
17	P 0080	exhaustVCPhydraulic pressure control valve coil high voltage
18	P 0107	Intake pressure sensor circuit low voltage or open circuit
19	P 0108	Intake pressure sensor circuit high voltage
20	P 0112	Intake temperature sensor circuit low voltage
21	P 0113	Intake temperature sensor circuit high voltage or open circuit
22	P 0117	Coolant temperature sensor circuit low voltage
23	P 0118	Coolant temperature sensor circuit high voltage or open circuit
24	P 0122	Electronic throttle valve position sensor1#circuit low voltage
25	P 0123	Electronic throttle valve position sensor1#circuit high voltage
26	P 0130	Front oxygen sensor open circuit
27	P 0131	Front oxygen sensor short circuit to low voltage
28	P 0132	Front oxygen sensor short circuit to high voltage
29	P 0133	front oxygen sensor responds too slowly
30	P 0134	The front oxygen sensor has too few dense conversion times
31	P 0136	Rear oxygen sensor open circuit
32	P 0137	Rear oxygen sensor short circuit to low voltage
33	P 0138	Rear oxygen sensor short circuit to high voltage
34	P 014C	front oxygen sensor dense thick-thin conversion times is too slowly
35	P 014D	front oxygen sensor dense thin-thick conversion times is too slowly
36	P 0171	Non-idle fuel system is too thin
37	P 0172	Non-idle fuel system is too thick
38	P 0222	Electronic throttle valve position sensor2#circuit low voltage
39	P 0223	Electronic throttle valve position sensor2#circuit high voltage
40	P 0230	Fuel pump relay fault
41	P 0261	1^st cylinder fuel injector circuit low voltage fault
42	P 0262	1^st cylinder fuel injector circuit high voltage fault
43	P 0264	2^ndcylinder fuel injector circuit low voltage fault
44	P 0265	2^st cylinder fuel injector circuit high voltage fault
45	P 0267	3^rd cylinder fuel injector circuit low voltage fault
46	P 0268	3^st cylinder fuel injector circuit high voltage fault
47	P 0270	4^thcylinder fuel injector circuit low voltage fault
48	P 0271	4^st cylinder fuel injector circuit high voltage fault
49	P 0300	Single cylinder or multi-cylinder miss fire
50	P 0324	Knock control system failure
51	P 0325	Knock sensor failure
52	P 0335	Crankshaft position sensor circuit no signal
53	P 0336	Crankshaft position sensor circuit signal interfere
54	P 0340	Camshaft position sensor line without signal/Intake VCP camshaft position sensor state diagnosis
55	P 0341	Camshaft position sensor line rationality failure/intakeVCPtarget wheel fault diagnosis
56	P 0351	Ignition coil "A" disconnects (1 cylinder)
57	P 0352	Ignition coil "B" disconnects (3 cylinder)
58	P 0353	Ignition coil "C" disconnects (4 cylinder)
59	P 0354	Ignition coil "D" disconnects (2 cylinder)
60	P 0366	exhaustVCPtarget wheel－CAMsensor fault
61	P 0401	Insufficient EGR flow
62	P 0402	Excessive EGR flow
63	P 0403	EGR control circuit failure
64	P 0404	EGR opening error is big
65	P 0405	EGR sensor lines open or short to low voltage
66	P 0406	EGR short circuit to high voltage
67	P 0420	Catalytic converter is too inefficient
68	P 0458	Carbon canister electromagnetic valve short circuit to low voltage or open circuit
69	P 0459	Carbon canister electromagnetic valve short circuit to high voltage
70	P 0480	Low speed fan failure
71	P 0481	High speed fan failure
72	P 0500	Speed signal source failure (speed signal comes from TCM/ABS/ESP through CAN)
73	P 0504	Brake switch relativity fault
74	P 0506	Idling engine speed too low
75	P 0507	Idling engine speed too high
76	P 0557	Brake power vacuum pressure sensor short-circuit to low voltage or disconnect
77	P 0558	Brake power vacuum pressure sensor short circuit to high voltage
78	P 0562	System voltage is low
79	P 0563	System voltage is high
80	P 0564	Cruise control input line fault
81	P 0565	Cruise“On/Off”signal interference
82	P 0566	Cruise“Cancel”signal interference
83	P 0566	Cruise“Cancel”signal embedded
84	P 0567	Cruise“Resume”signal interference
85	P 0567	Cruise“Resume”signal embedded
86	P 0568	Cruise“Set”signal interference
87	P 0568	Cruise“Set”signal embedded
88	P 0571	The switch state of the brake lamp has not changed during braking
89	P 058A	Battery sensor failure (from LIN)
90	P 0598	Electronic thermostat heating control circuit low voltage
91	P 0599	Electronic thermostat heating control circuit high voltage
92	P 0601	ROM error
93	P 0602	ECM programme error(Software version does not match)
94	P 0606	ECM processor fault
95	P 0606	ECM processor fault
96	P 0606	ECM processor fault
97	P 0606	ECM processor fault
98	P 0606	ECM processor fault
99	P 060A	ECM processor fault
100	P 060A	ECM processor fault
101	P 060A	ECM processor fault
102	P 0616	Starting motor relay circuit high voltage
103	P 0617	Starting motor relay circuit low voltage
104	P 0630	VIN code not written or incorrect
105	P 0633	The alarm failed to learn
106	P 0641	ETC reference voltageA#amplitude
107	P 0646	Air conditioning clutch relay short circuit to low voltage or open circuit
108	P 0647	Air conditioning clutch relay short circuit to high voltage
109	P 0651	ETC reference voltageB#amplitude
110	P 065C	Generator mechanical fault
111	P 065B	Generator electrical failure
112	P 0685	Main relay fault
113	P 0685	Main relay fault
114	P 0831	Low voltage (short connection) of clutch switch circuit
115	P 0832	High voltage of clutch switch circuit (short connection to power or circuit breaker)
116	P 0A3B	The generator is too hot
117	P 1167	Excessive thick when front oxygen decelerating and cutting off fuel
118	P 1171	Excessive thin when front oxygen accelerating and concentrating
119	P 1336	58 tooth gear wheel error not learning
120	P 1404	The EGR valve failed to return to the closed state
121	P 1404	The EGR valve failed to return to the closed state
122	P 1515	The starter state input is disconnected
123	P 1516	ETC drive steady state diagnosis fault
124	P 1561	Transmission chain status inputs short low
125	P 1562	Transmission chain status input short high
126	P 1563	Logic diagnosis drive chain status StuckLow
127	P 1564	Logic diagnosis drive chain status Stuckhigh
128	P 1566	Start/stop main switch Signal bonding
129	P 1567	The battery temperature is too high
130	P 1615	Start the relays open
131	P 1616	start relay bonding
132	P 2101	ETC drive second order diagnosis fault
133	P 2104	Engine forced idling
134	P 2105	Engine forced stop
135	P 2106	Engine function limited
136	P 2110	Engine power management
137	P 2119	Electronic throttle valve return fault
138	P 2122	Electronic accelerator pedal position sensor1#circuit low voltage
139	P 2123	Electronic accelerator pedal position sensor1#circuit high voltage
140	P 2127	Electronic accelerator pedal position sensor2#circuit low voltage
141	P 2128	Electronic accelerator pedal position sensor2#circuit high voltage
142	P 2135	Electronic throttle valve position sensor1#、2#circuit related fault
143	P 2138	Electronic accelerator pedal position sensor1#、2# circuitrelated fault
144	P 2187	idle fuel system is too thin
145	P 2188	idle fuel system is too thick
146	P 2300	Ignition coil "A" shorted to low voltage (1 cylinder)
147	P 2301	Ignition coil "A" shorted to high voltage (1 cylinder)
148	P 2303	Ignition coil "B" shorted to low voltage (3 cylinder)
149	P 2304	Ignition coil "B" shorted to high voltage (3 cylinder)
150	P 2306	Ignition coil "C" shorted to low voltage (4 cylinder)
151	P 2307	Ignition coil "C" shorted to high voltage (4 cylinder)
152	P 2309	Ignition coil "D" shorted to low voltage (2 cylinder)
153	P 2310	Ignition coil "D" shorted to high voltage (2 cylinder)
154	P 2A01	rear oxygen sensor decelerating and breaking response too slowly
155	U 0001	CAN network communication failure(C001)
156	U 0028	LIN communication failure (C028)
157	U 0073	CAN bus close(C073)
158	U 0121	Communication loss between ECU andABScontrol module(C121)
159	U 0126	Communication between ECM and steering Angle sensor is lost(C126)
160	U 012D	Communication loss between ECU and intelligent generator (C12D)
161	U 0131	Communication loss between ECU and power steering control module(C131)
162	U 0140	Communication loss between ECU and car body control module(C140)
163	U 0167	The burglar didn't respond(C167)
164	U 029A	Communication between ECU and battery sensor is lost(C29A)
165

2.Faults diagnosis flowchart

note:

■Before disassembling and installing any components, read the fault code first and then disconnect the negative terminal of the battery。

■Turn off the ignition switch before disconnecting the wiring harness from the battery terminal。 If the battery wiring harness is disconnected while the engine is working or the ignition switch is turned on, ECM will be damaged

■The wire harness between the ECM and the sensor shall be shielded by an earth wire connected to the body to prevent the ignition system interference and radio interference。 If the shielding harness fails, the harness must be replaced.

■When checking the charging status of the generator, do not disconnect the positive electrode of the battery to prevent ECM damage.

■When charging the battery with an external charger, disconnect the battery connection to prevent damage to ECM

3.3 Structure Principle and Maintenance of the Engine Electric Components

The electronic components covered in this section mainly include sensors, actuators and ECM. This section mainly describes the working principle of electronic components, structure, circuits and related maintenance.

The sensor's basic circuit generally has 3 wirings of power, signal and ground. Some sensors do not need a power supply, or the power circuit is built into the ECM, so that they only have the signal and ground two wirings. If they use the shell of iron, there may be only one link to the ECM signal line, so that the circuit is very simple, and some sensors circuit is very complex. The complexity of the sensor circuit depends on the type and structure principle of the sensor, the main sensors in the engine electronic control system are switch type, resistor type, pulse type, voltage type and so on.

Switch-type sensor is a simple structure sensor, usually has two terminals. Its circuit has the iron-and power-type two, of which the iron-type circuit is the end of the switch to the grounding, and the power-type circuit switch to the end of the power supply.

Resistive sensor is the most widely used sensor in electronic control system. Its structure has variable resistor type, potentiometer, etc., generally using the principle of DC circuit partial pressure to generate electrical signals. In order to ensure the accuracy of the signal, the ECU provides a constant size of the reference voltage as its operating voltage (generally 5V).

Variable resistance sensor has 2 terminals, generally the iron-type circuits, the end of which is the signal end, the other end of the iron-end; the potentiometer sensor has 3 terminals, respectively, the power supply end, signal end, and the iron end. Pulse sensor has a variety of principles and structural forms, such as the electromagnetic using electromagnetic induction principle, photoelectric using photoelectric principle, hall-style using Hall-effect, and the magnetic resistance type using principle of reluctance, etc., the circuit is very complex.

The voltage sensor usually uses the electrochemical principle and the piezoelectric effect to change the measured parameters into electromotive force. Most voltage sensors do not require operating power.

Electronic control system actuators are mainly solenoid valves, motors, relays, transistor switching circuits, lights and so on. Actuator circuit is usually relatively simple. It is generally only the power and ground wiring. The ECM uses ground control for most actuators. The power source for this actuator comes from the battery and the ground wire to the ECM.

3.3.1 Air inlet temperature pressure sensor

1.Elements instruction

1）MT62.1 electric injection system adopts velocity density air measurement method to detect the amount of air entering the engine, so as to control the fuel injection pulse width and accurately control the engine power output. The sensor is composed of an inlet absolute pressure sensor and an inlet temperature sensor.

2）The inlet absolute pressure sensor (MAP) is a pressure-sensitive variable resistance. Internal pressure diaphragm of air inlet pressure sensor and a magnet placed inside the coil heart are linked together, when the intake pipe inlet pressure change, the diaphragm will drive the core to move, the output voltage of the sensor is changed, ECU can convert the air intake of the starting motor according to the output voltage of the sensor, engine based on this signal, refer to other signals for engine fuel injection quantity control. MAP sensors are also used to measure atmospheric pressure at start-up and allow ECM to adjust automatically at different altitude under certain conditions. The ECM provides a 5V voltage to the MAP sensor and receives the voltage from the signal line. The sensor provides a circuit to ground through its variable resistance. The MAP sensor input signal affects the ECM's control of fuel output and ignition timing.

3) the inlet temperature sensor is a thermistor with a negative temperature coefficient (NTC).The resistance decreases with the increase of inlet temperature. The engine ECU monitor the change of inlet temperature through an internal comparison circuit.

n working pressure range：10kPa～115kPa

n Working temperature range：-40～125℃

2. Sensor installation position

Install on the intake manifold.

3.Sensor circuit diagram

Terminal 39: 5v power voltage signal

Terminal 43: manifold pressure sensor signal

Terminal 45: power grounding

Terminal 15: air inlet temperature sensor signal

Working voltage:5±0.1V

4、Installation precautions

■Absolute pressure sensor self-tapping bolts’ tightening torque: (6±0.5) N·m

■Make sure the sensor is fully attached to the intake manifold

■ Prohibit brutal disassembly.

5.Failure phenomenon and judgment

●Symptom: the fuel injection function of the ECM of the engine will be abnormal. If the air mixture is too rich or too thin, the engine will not run normally or accelerates idly and the exhaust pipe will emit black smoke and so on.

●General Fault Cause: The internal circuit of the sensor is disconnected, or the dirt accumulates, and the air inlet pipe leaks that causes the incorrect signal.

●Inspection methods:

1）Exterior inspection

Check whether the sensor harness connector is well connected, solid and reliable.

Whether the appearance is good, and confirm that there is no impact marks. Check if the sensor detection hole is blocked.

2）Circuit detection

①　Turn the ignition switch off and unplug the sensor end harness terminal.

②　Turn the ignition switch on and measure the terminals of the sensor harness connector separately with a digital multimeter.

③　Sensor power supply terminals should be measured as 5V reference voltage. If the voltage value does not match, it indicates that the control circuit or ECM has faulty, and it should be further tested.

④　When the sensor terminal is measured, the negative resistance between the battery and the battery should be less than 3Ω, if abnormal, the ground line should be repaired.

⑤　If the above check is not normal, turn off the ignition switch, unplug the harness ECM connector, check the wiring harness between the sensor connector and the ECM connector for the existence of disconnection, and the line phenomenon.

3.3.2 Coolant temperature sensor

1.Component Description

Engine coolant temperature sensor detects engine coolant temperature and transmits signal to ECM for start-up, idling, normal operation, injection timing and fuel injection pulse width control, while providing water temperature signal to instrument, for instrument water temperature display. It uses a thermistor with a negative temperature coefficient, whose resistance decreases with temperature. The ECM determines the temperature of the coolant by the output voltage of the sensor and provides the engine with the best air-fuel ratio mixture.

2.Installment position

3.Elements Circuit Diagram

Pin A: Output coolant temperature signal

Pin C: Ground

Pin B:Vain

Resistance value (Ω)

The resistance between A and C varies with temperature
temperature	Standard resistance（Ω）
-10	21371
25	2795
85	283
115	115.7

4.Installation precautions

①　■ Thread sealing with thread sealant;

②　Tighten torque:20±4N·m；

③　Start and idle the engine, Visually check engine coolant for leakage.

5.Failure phenomenon and judgment

●fault phenomenon: When the water temperature sensor fails, the mixture concentration will be affected. When the temperature signal sent to ECU by the water temperature sensor is lower than the actual temperature of the engine, it will lead to excessive mixing gas, exhaust black smoke, hot car idling instability, etc. when the water temperature signal of water temperature sensor is higher than the actual engine water temperature, will lead to mixed gas is too thin, cold start difficult, cold car idling instability and other failures. When the water temperature sensor has a short circuit or break fault, the fault self-diagnosis circuit of ECM will detect this fault, so that the engine fault attention lamp is on, and ECM will start the failure protection function.

●General fault reasons: Short circuit, open circuit, the output signal voltage and the standard value does not meet.

●Inspection methods:

1）Exterior inspection

2) Circuit detection

①　Turn the ignition switch off and unplug the sensor end harness terminal.

②　Turn the ignition switch on and measure the terminals of the sensor harness connector separately with a digital multimeter.

④　When the sensor terminal is measured, the negative resistance between the battery and the battery should be less than 3Ω, if abnormal, the ground line should be repaired.

3）Performance Test

Unplug the sensor harness connector and remove the sensor. Place the sensor in water, measure the resistance between the sensor terminals at different temperatures when heating, if it is not corresponding to the standard value, the sensor should be replaced.

3.3.3 Electronic throttle valve

1.Elements instruction

Electronic throttle valve assembly is one of the main components of intake control management system in modern engine management system. It directly controls the total intake of the engine, and then controls the engine speed and output power.

The electronic throttle valve eliminates the mechanical control mechanism of the mechanically controlled throttle body. Electronic throttle valve include drive motors, drive gear mechanisms, necessary mechanical transmission components and more powerful special throttle valve position sensors.

As one of the security guarantees of the system, The system is provided with a double output throttle valve position sensor, and a throttle valve position sensor increases with the opening of the throttle valve body. The output voltage signal of another throttle valve position sensor decreases with the increase of throttle valve opening.

2.Installment position

Install on the intake manifold.

3.

Elements Circuit Diagram

Terminal number	Function
A	5V power supply
B	Throttle motor control（+）
C	Throttle motor control（-）
D	TPS1 signal
E	TPS2 signal
F	Grounded

●Measuring range of throttle valve position sensor：Idle condition PS1 is 6%～14%，TPS2 is 86%～94%；Full open condition is TPS1为86%～94%.

●Throttle valve response time：≤100ms（full open to close），≤150ms（full close to open）

4、Installation precautions

■Fastening torque：10±1N·m；

■after re-installation, be sure to self-learning；

■ Prohibit brutal operation and damage to the shell and related sensors.

5.Failure phenomenon and judgment

Fault phenomenon: Throttle valve failure will cause that the engine idling operation not normal (such as idle speed too high or too low, idling unstable, idling easily flameout) or engine acceleration is not normal (such as the acceleration of the engine shaking, acceleration response delay, etc.), sometimes it can lead to the engine in the process of intermittent jitter and other phenomena.

●Fault cause: The potentiometer in the sensor is open or shorted, the motor can not normally open or close because of the fault, the throttle valve has too much carbon deposit, and the control function of ECM is abnormal.

●Inspection methods:

1）Exterior inspection

Check whether the sensor wiring harness plugs are connected well, solid and reliable; whether the sensor installation is loose or off; whether the appearance is good. Make sure there is no impact traces. Slide valves to check whether the rotation is smooth, with or without catching phenomenon. Check whether there is too much carbon deposit in throttle valve.

2) Circuit

①　Turn the ignition switch off and unplug the sensor end harness terminal.

②　Open the ignition switch, measure the position sensor harness wire harness plug terminals with a digital multimeter;

④　When the sensor terminal is measured, it should be the conduction state between the battery and the battery , if abnormal, the ground line should be repaired.

3）Position sensor resistance detection

Sensor resistance can be detected with an electronic multimeter. The detection method is as follows:

①　Turn the ignition switch off and unplug the sensor end harness terminal.

②　Use a multimeter to measure the total resistance of the potentiometer on the sensor harness socket. If there is short circuit, broken circuit or resistance value does not meet the standard, that means the potentiometer is faulty.

③　Measure the resistance of the potentiometer sliding contact to the ground terminal. The resistance should change smoothly with the opening or closing of throttle valve, otherwise the potentiometer is faulty.

3.3.4 Hall sensor

1.Component Description

The camshaft position sensor and crankshaft position sensor are hall sensors, work with the signal wheel on the camshaft and crankshaft. The signal wheel corresponds to a specific position of the engine. ECU uses the sensor's digital voltage signal to determine engine operating conditions and implement one-to-one control.

2.Installment position

They are respectively installed near the camshaft and crankshaft.

3.

Elements Circuit

捕获3

A：output B：ground C：power

■Working temperature:-40～150℃

■System input voltage: 5.0v (powered by the controller);

■ Working clearance: 0.1-1.5mm。

4.Installation precautions

■Pay attention to installation clearance;

Standard value:0.5~1.5mm

■Tightening torque:9 ~ 11N · m.

■after re-installation, be sure to self-learning；

5.Failure phenomenon and judgment

●Fault phenomenon：If the hall position sensor is input error signal, it can not inject fuel in order, which is easy to cause engine flameout, idling instability and acceleration weakness.

●General failure reason：The internal component of the sensor is damaged, or the internal circuit is broken or short-circuit, unable to generate signals; The external circuit of the sensor is broken or short-circuited; The installation position of the sensor is not correct, and the gap between the sensor and the rotor is too large, resulting in abnormal output signal.

●Inspection methods:

1）Exterior inspection

Check whether the sensor harness connector is well connected, solid and reliable. Whether the distance between the Hall element and the signal wheel meets the standard requirements, whether there is dirt or iron between them, if so, they should be removed.

2）Circuit detect: The hall sensor must be able to produce a signal when the power is in normal condition, so please check its power circuit and the ground circuit first.

①　Turn the ignition switch off and unplug the sensor end harness terminal.

②　Turn the ignition switch on and measure the terminals of the sensor harness connector separately with a digital multimeter.

③　Measure the sensor power terminal with 5V reference voltage. If the voltage value does not match, it indicates that the control circuit or ECM has faulty, and it should be further tested.

④　When the sensor terminal is measured, it should be the conduction state between the battery and the battery , if abnormal, the ground line should be repaired.

3.3.5 Oxygen sensor

1.Component Description

The oxygen sensor is used to provide information on whether the fuel injected into the engine cylinder has excess oxygen after it is completely burnt in the air inhaled. ECU can make use of this information with infinite loop control of the fuel quantity, has resulted in a three main engine exhaust of toxic ingredients can get maximum conversion and purification in three-way catalytic converter.

Its sensing component is a ceramic pipe with pores, the outside of the pipe wall is surrounded by the engine exhaust, and the inside opens to atmosphere. The sensor indirectly calculates the pulse width of fuel injection according to the difference of oxygen concentration on the inside and outside, and sends it to the ECU, which controls the injection again. At the same time, the output data of the oxygen sensor are detected, and the data of the oxygen sensor before and after are compared within the ECU to monitor whether the work of ternary catalysis was good.

The operating voltage of oxygen sensor fluctuates between 0.1-0.9v, and it should change 5-8 times in 10 seconds. If the frequency value is lower than this, the sensor is aging and needs to be replaced,it can not be repaired.

2.Installment position

The front (upstream) oxygen sensor is installed on the exhaust manifold before the three-element catalytic converter, and the back (downstream) oxygen sensor is installed after the three-element catalytic converter.

3.Elements Circuit

A：signal to ground B：signal output C：heating end- D：heating end+

4.Installation precautions

■Plug the installation hole of oxygen sensor with hairless cotton yarn to prevent sundries or oil and water from entering the exhaust manifold.

■Tightening torque :35±5N·m；

■It is forbidden to drop oxygen sensor or collide with hard surface.

■Carbon dioxide, silicone oil, engine oil, lead, paint, or other organic contaminants, which are released from the engine, are forbidden to pollute the sensor.

■Do not pull the wire when installing.

■Do not knot, pinch, or otherwise damage the sensor harness wire.

■Do not use grease, detergent or other impurities on the connector

5.Failure phenomenon and judgment

●Fault phenomenon: once the oxygen sensor and its connecting line malfunction, it will not only make the emission exceed the standard, but also worsen the working condition sometimes, cause the idle speed to be unstable or flameout, exhaust pipe to emit black smoke and so on.

●Common failure reasons: oxygen sensor poisoning, surface area carbon deposit, oxygen sensor internal circuit breakage, heater failure and so on.

●Inspection methods

1）Measure heating resistance of oxygen sensor

Turn ignition switch to “OFF”, disconnect wiring harness connector of oxygen sensor, use multimeter to measure resistance between C, D terminal of oxygen sensor. The resistance should accord with standard value（about 9.6Ω）.

2）Check voltage of oxygen sensor heater

Turn on the ignition switch and test the heating power supply voltage of the sensor with a multimeter. The standard value should be 12V.

3）Check whether the connection of several wires on the sensor is good, whether there is short-circuit, open-circuit , etc.

3.3.6 Fuel injector

1.Component Description

Fuel supplied from the fuel pump is stored and distributed through the oil pressure guide rail assembly, It provides a stable pressure environment for the fuel system, for the fuel system to provide a relatively stable pressure environment, make each cylinder oil pressure and oil balance, smooth engine operation. The fuel injector sprays the fuel according to the signal sent by ECM, and the amount of fuel injection is determined through the opening time of the solenoid valve of the injector.

2.Installment position

Installed on the fuel rail.

■Standard resistance between two terminals：11~16Ω

3.Installation precautions

■The installation of the oil injector is done by hand. It is forbidden to hit the oil injector with hammer or other tools.

■When disassembling and reinstalling the injector, the o-ring must be replaced and the sealing surface of the injector must not be damaged;

■After disassembly, the injector seat should be cleaned to avoid pollution.

4.Failure phenomenon and judgment

■ fault phenomenon: engine power down, idling shaking, starting difficult or even no start. The engine is high in fuel consumption and will emit black smoke when serious

●General fault reason：The carbon deposits of the fuel injector result in leakage or poor injection conditions, and the solenoid coil is damaged and cannot work. The injector leaks oil.

●Inspection methods

1）Electromagnetic coil detection

The electromagnetic coil resistance is measured with a multimeter, 11 ~ 16 Ω resistance.

2）Exterior inspection

Check whether or not the fuel injector has carbon deposition and other phenomena.

3）Control signal detection

Connect the positive and negative poles of the light-emitting diode test lamp to the power line and the ECM connection line of the fuel injector respectively. When the engine is running, the light-emitting diode test lamp should be shining. If it is not shining, it indicates that the control circuit of the fuel injector is malfunctioning, and the control circuit should be further overhauled. If there is an electric pulse in the control circuit during measurement but the injector does not spray oil, that means the injector is faulty.

4）Control circuit detection

①　Turn on the ignition switch and unplug the fuel injector wire bundle. The power ends supply voltage should be 12V.Otherwise, it indicates that the power circuit of the fuel injector is broken, and it should further check whether or not the power fuse is burnt out 、the main relay of the electric control system of the engine is faulty.

②　If the fuel injector does not spray oil under the normal condition of the power circuit, check whether the line from the fuel injector to ECM is broken. When checking, the ignition switch should be closed first, the wire bundle plugs of each fuel injector should be removed, and the circuit between each fuel injector and ECM should be measured with a multimeter according to the circuit diagram.

③　

3.3.7 Knock sensor

1.Component Description

2.The knock sensor is installed on the side of the cylinder block, generally between 2 and 3 cylinders, which is conducive to the engine detonation balance, The ECU uses the vibration frequency signal outputted by the detonation sensor to filter through the internal ECU, so as to judge whether the engine has a knock or not. When the knock signal is detected, the ECU gradually reduces the ignition advance Angle until no knock occurs, and then gradually recovers until the knock edge, so repeatedly. Installment position

installed on the side of the cylinder block, generally between 2 、3 cylinders.

3.Elements Circuit Diagram(see right)

1 - signal ground terminal

2 - signal output terminal

4.Installation precautions

■Bolts’ tightening torque: (22.5±2.5) N·m

■Do not drop or damage the sensor。

5. Failure phenomenon and judgment

●fault phenomenon：make noise and reduce engine power.

●General fault reason：The knock sensor is damaged, there are the short circuit、broken circuit、fastening bolts are not tightened as required.

●Inspection methods

1) Exterior Inspection

Check whether or not the fastening bolts are tightened as required, whether or not there is any sundries on the sensor and cylinder joint surface.

2) Circuit inspection

Close the ignition switch, unplug the wire harness plug of the knock sensor, and check whether or not there is short circuit or open circuit between the signal wire and ECM terminals by comparing the circuit diagram. If abnormal, it should be repaired.

3）Performance check

Disconnect the cord plug of the detonation sensor and tap with a small hammer on the cylinder body of the detonation sensor attachment, At the same time measure the voltages between the signal output end and the iron end of the sensor with the millivolt of the digital multimeter. If the voltage is generated during tapping, that means the sensor is good, otherwise it should be replaced.

3.3.8 Continuously variable CAM phase regulator and control valve

1.Component Description

Continuously variable CAM phase regulator is used to change the timing of the gas distribution mechanism. It can continuously adjust the phase relationship between camshaft and crankshaft according to the needs of the control system and realize the control of gas distribution phase.

VVT pressure regulating control valve is a four-way pulse width control solenoid valve that can move in both directions. The oil flow can be controlled by the axial movement of the plunger valve. The engine ECU changes the oil flow to both sides of the rotor blade through the duty ratio signal regulated by pulse width, thus controlling the timing and phase of the CAM relative to the crankshaft.

2.Installation location (see below)

_DSC2480

3.Element Parameters

■VCP operating conditions

Items	Value
Input voltage	11.5-18.0V
Average working current while holding position	1.0A
Maximum current	In the case of 100% duty ratio, -40ºC, 15.5v;2.5A
Environment temperature	-40 to 150ºC
Cover interior temperature	-40 to 150ºC
Solenoid valve temperature	-10 to 150ºC

■OCV valve operating conditions

Type	Engine oil pressure control solenoid valve
Coil resistance	nominal：5.6Ω（-30 ºC） 7.0 Ω（20 ºC） 10.6 Ω（150 ºC）
Minimum current required for full stroke of plunger valve	1A
Input voltage(through the coil)	nominal：13±0.5V min：11.0V max：18.0V
Starting response under normal input voltage	<50ms,temperature<65ºC
Close the response	<50ms,temperature<65ºC

4.Installation precautions

■OCV Bolts’ tightening torque: (6±1) N·m

■During installation, apply a proper amount of lubricating oil on the o-ring of OCV before installing OCV.

5.Failure phenomenon and judgment

●Fault phenomenon: when the valve timing control system fails, the actual valve timing will not match the target valve timing of ECM, which will affect its power performance and emission performance.

●General failure reasons: OCV valve electromagnetic coil open circuit 、short circuit、valve core clamping stagnation, etc.

●Inspection methods

1）Measure the resistance of solenoid coil of OCV valve

the resistance between the two pins of OCV is measured by multimeter and the resistance is 8Ω.

2）Dynamic check

Power the OCV valve terminal by 12V to check whether or not the slide of the OCV mid-column slide valve is stuck.

3.3.9 Carbon canister solenoid valve

1.Component Description

The gasoline vapor produced in the fuel tank is piped into the activated carbon canister, which can absorb the gasoline molecules in the gasoline vapor. Another outlet hose on the activated carbon canister is connected to the engine air inlet pipe. The carbon canister solenoid valve in the middle of the hose controls the opening and breaking of the line When the engine is running, if the solenoid valve opens, under the action of vacuum suction within the inlet pipe, air enters beneath the canister, pass the activated carbon from the upper outlet through the hose into the engine inlet pipe,revaporize the gasoline molecules attached to the surface of the activated carbon, The air is sucked into the engine to burn, allowing the fuel to be fully used. At the same time, it can restore the adsorption capacity of activated carbon in the carbon canister, and it will not be invalidated due to too long use.

2.Installment position

Install on air inlet manifold bracket. (see below)

_DSC2507

3.Installation precautions

■Avoid water, oil and other liquids entering the valve during maintenance.

■Pay attention to the direction of installation.

4.Failure phenomenon and judgment

●fault phenomenon：The first is the failure, that is, the fuel vapor in the fuel tank cannot be recovered, there is a fuel smell in the car during the summer driving; Second, the work is abnormal, such as when the fuel vapor recovery work in the engine idle speed, results in too much mixture or influence the engine idle speed stability.

●General fault reason：The solenoid valve is not working normally, it is closed continuously, the solenoid valve is often opened, and the solenoid valve is blocked.

●Inspection methods:

1）Measure the resistance

the resistance between the two pins of charcoal canister solenoid valve is measured by multimeter and the resistance is 19~22Ω（20℃）.

2）Performance check

Unplug the cable bundle plug of the solenoid valve and blow air into the solenoid valve. The solenoid valve should not be ventilated. Connect the 12V power supply to the two terminals of the solenoid valve and blow air into the solenoid valve at the same time. The solenoid valve should be able to ventilate. If there is any abnormality, it indicates that the solenoid valve is out of order.

3.3.10 EGR valve

1.Elements instruction

The EGR is built to return a small fraction of the waste from gasoline engines to the cylinder. The inert gas of recirculating waste gas will delay the burning process and reduce the amount of oxynitride compounds. Because the change of waste recycling amount may have opposite effects on different pollution components, it will have a positive effect on emissions.

2.Installment position

IMG_20170719_143437

3.Installation precautions

■The gasket should be clean during installation to prevent air leakage

■Pay attention to the direction of installation.

4.Elements Circuit

Terminal1--power supply wire

Terminal 2-- grounding

Terminal 3--signal wire

Terminal 4--Solenoid valve+

Terminal 5--Solenoid valve-

5. common fault

■Difference between EGR valve opening set value and the actual value is higher than the upper limit (positive deviation is too large)

■EGR valve is stuck in a closed state

■Difference between EGR valve opening set value and the actual value is below the lower limit (negative deviation is too large)

6.Inspection strategy

A The H - bridge circuit of the EGR valve drived by ECU breaks,EGR valve is stuck in a closed position

B The H - bridge circuit of the EGR valve drived by ECU has positive or negative disconnection,EGR valve is stuck in a closed position.

3.3.11 Ignition coil

点火线圈

1. Overview

This engine adopts the independent electric control ignition system, the secondary coil of the ignition coil is directly connected with the spark plug. In this ignition system, each ignition coil is connected with ECM to calculate the ignition advance angle according to the signals of various sensors, and the piston positions of each cylinder are measured according to the crankshaft position sensor. According to the working order of each cylinder, the ignition signal is sent out to each ignition coil in turn. According to the ignition signal of ECM, the ignition coil of each cylinder controls the conduction and disconnection of the primary winding current of each ignition coil, so that the secondary high voltage is generated, which is directly sent to the spark plug for ignition.

The ignition coil consists of two sets of coils, primary coils and secondary coils, the main function of which is to turn the low voltage of the vehicle into high voltage.

2.Working principle

Ignition coil consists of primary winding resistance, secondary winding and iron core, shell, etc. When some primary resistance grounding is connected, the primary resistance is charged. Once the primary resistive circuit is cut off by ECU, the charge is suspended and a high voltage is induced in the secondary resistance to discharge the spark plug.

3、Installment position

Ignition coil is installed on engine cylinder head cover.

4、Installation precautions

Ø Packing, transport and assembly process can not be removed high pressure connecting rod.

Ø Fastening bolt torque: M6 6~10N.m

Ø Be sure to disconnect the battery negative electrode before installation and disassembly

5. Technical parameters and pin definitions

n Working voltage: +12V

n Primary coil resistance: 0.75Ω

n Stitch definition

Pin 1——Power supply

Pin 2——ECU control signal

Pin 3——Ground

6. Failure phenomenon and diagnosis method

l General fault reasons: short circuit or open circuit inside the coil, leakage of the coil, cracks in the shell, insufficient ignition energy caused by the aging of the coil, and breakdown of the coil;

l Fault phenomenon: ignition coil failure causes spark plug no fire or fire weak, cause engine work difficult to start, can not start or shake.

l Inspection methods

When there is a failure of individual cylinders to ignite, the ignition coil can be exchanged to determine the cause of component damage

or electric has fault. If all cylinders do not ignite, the cause of failure should be in the control circuit, sensor or ECU, and it is unlikely that all ignition coils will be damaged at the same time. Therefore, as long as the control circuit is detected, the fault range can be determined.

4）Control circuit detection

Disconnect wire harness plug of the ignition coil, turn on the ignition switch, and the measuring power supply terminal shall be 12V battery

voltage. If is 0V, indicating that the power circuit failure, should be further overhaul.

Measure grounding terminal of wiring harness connector, resistance between it and negative electrode of the battery should be less than 3Ω. If abnormal, it should be repaired.

Measure the signal terminal of the wire harness plug with a light emitting diode test lamp. When starting the engine, the test lights should flicker, otherwise the ECU does not send a ignition signal to the ignition coil. The crankshaft position sensor may be malfunctioning, or the ECU may not work and should be further overhauled.

5）Performance check

Remove the ignition coil, attach the spark plug and make it grounding. Start the engine and check whether there is high pressure spark in the spark plug electrode.

3.3.12 Spark plug

火花塞截图01

1. Overview

The role of the spark plug is to send the ignition coil to the pulse high voltage discharge, to break through the air between the two electrodes of the spark plug, and to produce an electric spark to ignite the mixed gas in the cylinder.

2.Working principle

The main parts of spark plug are insulator, shell, connection screw and electrode. Spark plug electrode consists of center electrode and side electrode, and the spark gap is between them. The high voltage current from the ignition coil passes through the central electrode and then discharges at the bottom end of the discharge gap.

3.Technical characteristics of the parameters

n Ignition clearance: 0.7~0.8mm

n Spark plug heat value: 6

n Resistance value between shell and connecting column: 6±3kΩ

4、Installation precautions

Ø During installation, hammers and other tools are prohibited

Ø Spark plug tightening torque: 23 ± 3N.m;

5、Failure phenomenon and judgment

General failure reasons: spark plug ablation and so on.

Fault phenomenon: it is difficult to start and shake.

Inspection methods:

Observe color:

Normal working spark plug, its insulator skirt is russet and relatively clean. If the spark plug shows the following symptoms, it indicates that the engine or spark plug is not working properly.

④　 Spark plug electrode melts and the body is white. This indicates that the high temperature in the cylinder causes spark plug ablation, which may be due to excessive carbon accumulation in the cylinder, too small valve clearance, too late ignition time, and too thin and damaged spark plug sealing ring. The spark plug failed to tighten according to the required torque, engine heat dissipation and so on.

⑤　Spark plug electrodes become round and insulator scarring. The reason is that the ignition time is too early, the octane number of gasoline is too low, and the heat value of spark plug is too high.

⑥　The top of the spark plug insulator is broken. This shows that the engine detonation combustion, instantaneous high pressure shock wave will break the insulator. The reason is that the ignition time is too early, the octane number of gasoline is low, the combustion chamber is serious carbon deposit and the temperature is too high.

⑦　The top of the spark plug insulator has gray and black stripes. This shows that the spark plug has cracked and leaked gas.

⑧　There are oily deposits between the tip of the spark plug insulator and the electrode. This indicates that the lubricating oil has entered the cylinder to participate in combustion. If only individual spark plugs have deposits , it is due to failure of single cylinder valve oil seal etc . If all spark plugs have carbon deposition , a systematic lubrication system and crankcase ventilation device will be considered.

⑨　There are black deposits between the tip of the spark plug insulator and the electrode. This indicates that the mixture does not burn well, mainly because the mixture is too dense, leaving the black soot layer on the spark plug.

⑩　There are gray deposits between the top of the spark plug insulator and the electrode, which is usually due to the gasoline quality does not meet the requirements, gasoline additives after combustion products, this type of sediment will reduce the spark plug ignition performance.

11　The flame-plug insulator skirt and electrode are moist and oily. This means that high voltage wire of the cylinder has no

power supply or weak electric energy.

3）Spark-over test:

Remove the spark plug, install it on the ignition coil, make the shell of the spark plug iron with the cylinder head, turn on the ignition switch, turn the engine with the starting device, and see if the spark plug is igniting. Generally speaking, as long as spark plug jump out of the spark is blue white or purple white, and in the fire at the same time issued a "patter" sound, indicating that the spark plug fire is stronger.

4）Measuring electrode gap:

The electrode gap of spark plug was measured with thick gauge or circular gauge, the standard value of 0.7 ~ 0.8 mm.

3.3.13 On-off Water Pump

电子水泵

1. Overview

Compared with ordinary water pumps, the on-off water pump according to the power On and off the electronic components of the switching water pump controlled by ECU realizes the separation between the pump pulley and the pump impeller,reduce the cold But fluid flow, in order to achieve the purpose of rapid warming.

2.Working principle

ECU powers on, the impeller coil is energized, the armature is absorbed by the electromagnetic force, the torque of the coil spring clutch disappears, and the water pump belt wheel is detached from the pump impeller. ECU powers off, impeller coil powers off, armature back, coil spring clutch clamping belt pulley, impeller rotation, the same as ordinary mechanical pumps.

3、Technical characteristics of the parameters

n Water pump service environment：water temperature：-40°C~120°C

n environment temperature：-40°C~135°C

n Working voltage：9-16V

n the minimum voltage for the clutch breaking away completely ：9V

4、Installation precautions

Before installation, check that the gear train turns flexibly without lag

5、Failure phenomenon and judgment

General fault reason:Clutch failure

Faults phenomena:high temperature

Remove the water pump, power off the pump, rotate belt pulley counterclockwise by hand, check whether the impeller is synchronous to rotating at the same time, if it does not rotate synchronously as the same in clockwise,that means the pump is damaged.

3.3.14 ECM

ECU is the control center of the electronic control system, this system is DELPHI MT62.1 control system, its functions mainly are the followings:

1.Receive signals from various sensors to obtain engine operating parameters and provide the basis for the control of engine systems.

2.According to various operating parameters of engine provided by the sensor, according to the set program and control strategy, output control signals to fuel injector, ignition coil and other actuators, so as to realize the control of each engine system.

3.Monitor sensors, control circuits, actuators and other signals of the electronic control system. When the signal is abnormal, light up the fault warning lamp to issue an alarm in time. At the same time, store the fault code in the memory of ECU, and start failure protection function to maintain the engine operation. In addition, the maintainer can trigger self-diagnosis function of ECU through specific steps, and read the fault code and data stream stored by ECU through the fault diagnosis connector, which can provide the basis for fault diagnosis.

Besides, ECU also has the function of controlling the power supply of the electronic control system and providing stable reference voltage for some sensors.

Electrical schematic map

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3.4 Engine Control System Common Fault Diagnosis

3.4.1 Electronic control system common failure and main causes

1. ECM failure

Under normal circumstances, ECM has a good reliability, and will not fail in normal use. Most failures of ECM are by not properly used or caused by improper maintenance. Main reasons of ECM failure are the following:

①　The ECM power circuit is faulty, causing ECM not to work.

②　Unplug the ECM harness connector while the power is on, causing ECM damage due to momentary high voltage.

③　The operation due to water or damp, resulting in ECM internal circuit short circuit or electronic components damaged; or the plug in the terminal is poor contact because of the oxidation.

④　The ECM interior is damaged. When the ECM is completely out of service due to damage and power failure, the engine failure warning light on the instrument platform won't light up when the ignition switch is turned on. The engine cannot start because it is not ignited and sprayed with oil.

⑤　If there is some damage to the control program of ECM or some of its input and output circuits are damaged, some of the functions of the electronic control system will be abnormal. For example, individual cylinders will not inject fuel and idling automatic control will fail.

2. Sensor failure

Sensor failures are in the following forms.

①　Internal sensor failures, such as the internal circuit open circuit, short circuit or internal components aging, damage and other failures.

②　External sensor control circuit failure, such as the sensor power circuit, ground circuit, the signal circuit of the short circuit, open circuit and so on.

③　Sporadic failures internal or external the sensor, such as poor contact of internal components or plugs, and occasional malfunctions at work.

When the sensor internal or external circuit is open or short circuit fault, the sensor signal value will exceed the normal range, this failure is easily measured by ECM self-diagnostic system. The ECM immediately lights the engine fault warning light on the dash and notes the fault code in memory and starts fail-safe control to maintain the engine running.

When the sensor internal components have aging damage, the signal value, although not beyond the normal range, does not meet with the actual parameters detected. This failure is sometimes not detected by ECM self-diagnostic system and fails to initiate fail-safe control, which can result in abnormal engine operation.

3.Actuator failure

Actuators containing both electronic components and mechanical parts inside, is the most prone to failure components in electronic control system . When an actuator fails, the ECM control commands will not be executed properly, causing the engine to malfunction. Common causes of failure are the following:

①　The electronic components in the actuator are damaged or the internal circuit is short-circuit、open-circuit or other hardware failure.

②　The mechanical parts in the actuator can not work normally due to wear and jamming.

③　Aging and other reasons in the electronic components or mechanical parts in actuator lead to slow response.

④　Actuator internal electronic components exist virtual connection or mechanical parts exist with the abnormal gap; the actuator occasionally malfunctions due to temperature or other external factors.

4. Control circuit failure

The abnormal control circuit between ECM and sensor, actuator, power supply and iron can also make the sensors, actuators and ECM of the electronic control system not work properly, and cause various faults of the engine. The main reasons of the common control circuit fault are as follows:

①　Power fuse due to bad contact, overload fuse and other reasons causes the system power circuit failure.

②　The grounding wire of a sensor, actuator, or ECM is poorly pitched, resulting in failures of sensor, actuator, or ECM abnormal operation.

③　The connector in the control circuit has been disassembled for many times, causing the plug or terminal to loosen、oxidate ,results in improper contact of the plug;

④　Connecting wire aging, internal fracture or skin rupture, resulting in open circuit or short circuit fault.

3.4.2 Electronic control system common fault diagnose

1.Engine can not be started

When ignition switch is ON, the starter can drive engine to turn normally, but can not start, and there is no sign of starting vehicle. Then it must be at least one of ignition control system, fuel control systems or ECM in engine electronic control system is completely disabled. If starter can drive engine to normal rotation, and there is a slight sign of starting vehicle, but can not start. It indicates that although function of ignition system, fuel control system and ECM is abnormal, but it is not completely functional. The reasons for this failure are that the high pressure spark is too weak or the ignition time is not correct, the mixture is too thin, the mixture is too thick, and the cylinder pressure is too low. The reasons for the failure of engine can’t start are usually the followings:

①　The fuel pump does not work.

②　Fuel injector does not work.

③　Ignition system does not ignite.

④　Fuel pressure is too low.

⑤　Ignition advance angle is incorrect.

⑥　High pressure spark is too weak.

⑦　Injector leaks oil.

⑧　ECM does not work.

Check Steps:

①　To failure of engine can not start, generally should first check fuel storage situation of fuel tank. if there is no fuel in the tank, it should be refueling.

②　Read fault code, according to the fault code to find the corresponding fault cause. The main components that may affect engine starting are crankshaft position sensor, coolant temperature sensor, inlet temperature pressure sensor and so on.

③　Check ignition system. If engine does not ignite, engine can not also start. Therefore, ignition system should be checked whether there is failure before further inspection.Refer to engine electrical equipment for specific operation

④　Check whether or not the injector is working properly.

⑤　Check whether fuel pump is working properly. Make electric fuel pump run artificially (temporarily supply it with a specified voltage). You should be able to hear the sound of fuel pump running or to feel the pressure pulsation of fuel when you hold the inlet pipe with your hand.

⑥　Check fuel pressure. he standard value should be around 350KPa

2. Engine hard to start

Engine starting difficulty refers to engine can drive engine to rotate in normal speed, there is obvious sign of vehicle starting, but can not start; or need to start several times; or need starter to drive for a long time before engine can start; or start after flameout, unable to normal running. Main reason for hard starting are in the followings:

①　The fuel pressure is too low, making the mixture too thin when starting.

②　Coolant temperature sensor failure, resulting in the mixture is too thin or too thick.

③　The injector leaks oil,resulting in bad spray atomization

④　Fuel injector is blocked, making the fuel injection amount is less or no, leading to the difficulty of starting.

⑤　Ignition timing is abnormal or poor performance of spark plug or ignition coil in ignition system.

⑥　There is failure in ECM starting control circuit.

⑦　The pressure of the cylinder is too low. The combustible mixture in the cylinder has poor combustion conditions and is not easy to fire.

Check Steps:

①　Read fault code, check fault code related components.

②　Check whether there is leaking in intake system. Check carefully to see if the relevant intake pipe is broken, the coupling clamps are loose, and the crankcase ventilation system hose is well connected.

③　Check whether idling related component is working properly.

④　Check fuel pressure, if the pressure is too low, check if fuel pump is working properly or the gasoline filter is blocked.

⑤　Check if the mixture is too thick during starting (black smoke, sharp unburned gasoline, etc.). If the mixture is too thick, check the fuel pressure, coolant temperature sensor, intake pressure sensor, etc.

⑥　If the mixture is normal, focus on the ignition system. Remove spark plug, check whether there is aging, serious carbon deposition or spark plug gap is too large in spark plug, these conditions may affect the starting performance. Check ignition control circuit to see if there are open circuit, short circuit and so on. Do fire test, if necessary.

⑦　Check the cylinder pressure. If the cylinder pressure is lower than 1.1Mpa, the engine should be disassembled and inspected for mechanical failure.

If all above are normal, try to replace ECM.

3. Engine idling unstable

If engine starts normally, its idle speed is unstable, the engine has obvious jitter and miss fire easily, regardless of whether it is cold or warm. This phenomenon may be caused by the following reasons:

①　Fuel pressure is low.

②　Poor atomization、oil leakage or blockage of the injector;

③　Spark plug working not well.

④　Air inlet temperature pressure sensor failure.

⑤　Charcoal canister solenoid valve works at idle speed.

⑥　Cylinder pressure is too low or cylinder pressure difference is too large.

Check Steps:

①　Read fault code and repair according to the fault code.

②　Check whether there is air leakage or pipe connections are connected properly in air intake system.

③　Check whether there is stuck, carbon deposit, oil or excessive dust when throttle valve working.

④　Do cylinder breaking test, cut off one cylinder one by one in idle speed , and check whether engine speed drop is equal. If engine speed of some cylinder is basically unchanged when the cylinder is broken, it indicates that the cylinder is not working well or not work. Check whether there is fault in cylinder ignition coil, spark plug or fuel injector, and whether there are faults in the related control circuit. Check cylinder pressure, if the cylinder pressure is abnormal, further check the valve clearance, cylinder wear and valve sealing.

⑤　Check fuel pressure, if abnormal please check the oil pump and related fuel lines.

⑥　Check air inlet temperature pressure sensor signal. If not normal, proceed to the next step.

4. Idling engine speed too high

Electric control system can let engine run in a faster speed when vehicle is cold, and let engine returned to normal idle speed when vehicle is warm. If engine still keeps high idle speed after warming vehicle, that is, the idle speed is too high, it usually has the following reasons.

①　Throttle failure or air leakage in intake pipe.

②　Accelerator pedal failure.

③　Coolant temperature sensor fault

④　Carbon canister solenoid valve failure

Check Steps:

①　Read fault code and repair according to the fault code.

②　Check whether there is stuck, carbon deposit in electronic throttle valve.

③　Check water temperature sensor.

④　When A/C switch is ON, if engine speed does not change, check whether the relevant vehicle control signal is normal.

⑤　Tighten hose connected to intake manifold, if engine speed decreases, it indicates that there is air leakage in the crankcase ventilation system or the carbon canister solenoid valve, so the pipeline and solenoid valve of carbon canister should be further checked.

5. Idling engine speed fluctuating too much

If engine speed fluctuates continuously during idling, it may be engine fuel system, ignition system or electronic throttle valve related failure. It can be considered from the following points.

①　Poor atomization or blockage of the injector;

②　Spark plug bad ignition.

③　Wrong water temperature sensor signal.

④　Oxygen sensor failure.

⑤　Electronic throttle valve or other control circuit failure.

Check Steps:

①　Read fault code Pay special attention to coolant temperature sensor, inlet temperature pressure sensor, oxygen sensor.

②　Whether there is electronic throttle - related fault code or not, if there is, check the corresponding sensors, actuators and their control circuits.

③　Disconnect each cylinder ignition coil or fuel injector wiring harness connector one by one during idling, check whether the engine cylinders work steadily. If engine speed drop is not obvious when disconnecting some cylinder ignition coil or fuel injector wiring harness connector, it indicates the cylinder work normally, should check spark plug, high voltage wire and fuel injector.

④　Measure resistance of coolant temperature sensor at different temperatures, and check whether accord with the standard value. If it is abnormal, the water temperature sensor should be replaced.

⑤　Check inlet temperature pressure sensor.

6. Easy to miss fire when idling

Main reasons for easy to miss fire when idling are the followings.

①　Ignition system is not working properly, it is easy to miss fire during engine running.

②　Fuel system works abnormally, such as low fuel pressure, abnormal fuel pump working, fuel injector blockage, and so on.

③　Idle speed instability or idling engine speed too low;

④　Electronic throttle valve fault;

⑤　Bad contact in wiring harness connector of control system circuit.

Check Steps:

①　Read fault code and check related parts according to the fault code.

②　Check whether there is lack power during driving, if there are acceleration weakness、 acceleration slow reaction; check fuel pressure, if it is abnormal, check fuel system related components.

③　If idle speed is unstable, or even flameout during idling when A/C is on, check whether or not there is failure in A/C switch, there is failure in ECU connecting circuit.

④　If all the above checks are normal, check whether there is bad contact in engine control wire harness.

7. Power not enough

Lack power means that vehicle accelerates slow, accelerator pedal is still insufficient, rotating speed is not high or climbing slope is weak, etc. Main reasons for the failure include the following points.

①　Air filter blocked or inlet system pipe connection loosen.

②　Electronic throttle valve fault;

③　Fuel pressure is too low.

④　Poor atomization or blockage of the injector;

⑤　Water temperature sensor fault

⑥　Temperature pressure sensor failure

⑦　wrong ignition timing or high pressure spark is too weak.

⑧　Abnormal cylinder pressure.

Check Steps:

①　Check whether there is blockage in air filter, whether air intake system connection is normal. If abnormal, should be handled.

②　Read the fault code and check the components associated with the fault code. Sensors and actuators that affect dynamic include water temperature sensor, air inlet temperature pressure sensor, spark plug, fuel injector, ignition coil, etc.

③　Check spark plug and ignition coil.

④　Check ignition timing.

⑤　Check fuel pressure, If pressure is too low, further check fuel pump, fuel line and so on.

⑥　Check the injector, See if there are serious problems such as carbon deposition.

⑦　Measure cylinder pressure.

3.5 Engine Control System Fault Diagnosis Process

3.5.1 Diagnose according to the fault code

1.Instruction

1) The following overhaul would be carried out only it has been confirmed as the current steady-state failure , otherwise will cause the diagnosis to be wrong.

2) The following "multimeter" occasion refers to the digital multimeter; prohibit the use of pointer multimeter on the electronic control system line inspection.

3) check vehicles with anti-theft system, if ECM replacement occurs in "next steps", pay attention to matching after ECM replacement.

4) If the fault code shows that the voltage of a circuit is too low, it means the circuit may be shorted or open to ground. If the fault code shows that a circuit voltage is too high, it means that the circuit may have a short circuit to the power supply. If the fault code shows a circuit fault, it means there may be a circuit break in the circuit or there are multiple line faults.

2. Fault diagnosing assist

1) If the fault code can not be cleared, the fault is a steady-state fault; if it is an occasional fault, check the harness connector for looseness.

2) In the overhaul process, do not neglect the impact of car maintenance、cylinder pressure、mechanical ignition timing and so on to the system.

3. Fault Code Diagnosis

■ Related ECM pins mentioned below refer to actual wiring harness diagram.

Fault code	P0012		Intake VCP camshaft phase is large
Set up emergency control plan:			Turn on the fault lights until the fault is gone
Wire connection terminal:				MT62.1	VCP control		Normal measuring signal
Variable timing control signal:				43	B		0～1000mV
Main relay:				\	A		12V
Judging condition		Possible fault reasons				Referred failure troubleshooting
Engine running failure duration time﹥2 seconds		1. Connectors are not plugged in 2. Variable timing control signal circuit has open circuit 3. Variable timing control signal circuit has short circuit to ground 4.Main relay circuit fault 5. Sensor damaged 6.Failure of timing control signal input interface on ECM				1. plug the connector again 2.repair wire harness 3.Repair wire harness 4.Repair wire harness 5.Replace the sensor 6.Replace ECM

Fault code		P0026	Intake VCP hydraulic pressure control valve vised
Set up emergency control plan:			Turn on the fault lights until the fault is gone,close air inlet VCP hydraulic pressure control valve.
Wire connection terminal:				MT62.1	VCP control		Normal measuring signal
Main relay:				\	A		12V
Variable timing control signal:				43	B		0-12V square wave
Judging condition	Possible fault reasons					Referred failure troubleshooting
duration time﹥2 seconds	1. Hydraulic control valve drive circuit has short circuit to the system power anode 2. Hydraulic control valve is damaged 3. ECM fault					1. Repair wire harness 2. Replace control valve 3. Replace ECM

Fault code	P0107		Intake pressure sensor circuit low voltage or open circuit
Set up emergency control plan:			Turn on the fault lights until the fault is gone When the engine stops：100kPa When the engine is idle：≈32kPa when engine is running:The manifold pressure changes with the throttle opening
Wire connection terminal:				MT62.1	Pressure sensor		Normal measuring signal
5V reference voltage:				39	2		5V
manifold pressure signal:				43	1		0.5～4.5V
Sensor signal ground				45	4		0V
Judging condition		Possible fault reasons				Referred failure troubleshooting
engine running No TPS fault MAP﹤14.017KPa RPM﹤1050 rpm TPS﹥18.75 % fault duration time﹥2.5 seconds.		1. The connector is not solid 2. Pressure signal circuit open circuit 3. Pressure signal circuit has short circuit to earth 4. 5V reference voltage circuit open 5. Sensor signal ground circuit open 6. 5V reference voltage is opposite the reference ground（This failure may cause sensor damage） 7. Sensor damage 8. MAP signal input interface fault on ECM				1. Plug again 2. Repair wire harness 3. Repair wire harness 4. Repair wire harness 5. Repair wire harness 6. Repair wire harness 7. Replace sensor 8. Replace ECM

Fault code	P0108	Intake pressure sensor circuit high voltage
Set up emergency control plan:		Turn on the fault lights until the fault is gone When the engine stops：100kPa When the engine is idle：≈32kPa when engine is running: The manifold pressure changes with the throttle opening
Wire connection terminal:			MT62.1	Pressure sensor		Normal measuring signal
5V reference voltage:			39	2		5V
manifold pressure signal:			43	1		0.5～4.5V
Sensor signal ground			45	4		0V
Judging condition		Possible fault reasons			Referred failure troubleshooting
Engine running no TPS fault MAP﹥98.117kPa TPS﹤19.141% fault duration﹥2.5seconds		1. The constrained pressure signal circuit is short-circuited to the 5V reference voltage or power positive pole 2. Sensor is damaged 3. Pressure signal input interface fault on ECM			1. Repair wire harness 2. Replace sensor 3. Replace ECM

Fault code	P0112		Intake temperature sensor circuit low voltage
Set up emergency control plan:			Turn on the fault lights until the fault is gone The air inlet temperature is equal to the coolant temperature，but is no more than 44.25 C.
Wire connection terminal:				MT62.1	temperature sensor		Normal measuring signal
Air inlet temperature signal:				15	3		0.5～4.5V
Sensor signal ground				45	4		0V
Judging condition		Possible fault reasons				Referred failure troubleshooting
Engine running time﹥120 seconds MAT﹥-38.25C fault duration time﹥2.5 seconds		1. The connector is not solid 2. The temperature signal circuit open 3. Sensor signal ground open 4. The temperature signal circuit is short-circuited to the positive pole of the power supply 5. Sensor damage 6. signal input interface fault on ECM				1. Plug again 2. Repair wire harness 3. Repair wire harness 4. Repair wire harness 5. Replace sensor 6. Replace ECM

Fault code	P0113		Intake temperature sensor circuit high voltage
Set up emergency control plan:			Turn on the fault lights until the fault is gone The air inlet temperature is equal to the coolant temperature，but is no more than 44.25 C.
Wire connection terminal:				MT62.1	Air inlet temperature sensor		Normal measuring signal
Air inlet temperature signal:				15	3		0.5～4.5V
Sensor signal ground				45	4		0V
Judging condition		Possible fault reasons				Referred failure troubleshooting
Engine running time﹥60 seconds MAT﹥148.5C fault duration time﹥2 seconds		1. Temperature signal circuit is short-circuited to earth 2. Sensor is damaged 3. Pressure signal input interface fault on ECM				1. Repair wire harness 2. Replace sensor 3. Replace ECM

Fault code	P0117		Coolant temperature sensor circuit low voltage
Set up emergency control plan:			Turn on the fault lights until the fault is gone Start with air inlet temperature，Fixed after increasing to 79.5 degrees over time
Wire connection terminal:				MT62.1	Coolant temperature sensor		Normal measuring signal
Coolant temperature signal:				20	A		0.5～4.5V
Sensor signal ground				46	C		0V
Judging condition		Possible fault reasons				Referred failure troubleshooting
Engine running time﹥10 seconds CTS﹤-38.25C fault duration time﹥2 seconds		1. The connector is not solid 2. The temperature signal circuit open 3. Sensor signal ground open 4. The temperature signal circuit is short-circuited to the positive pole of the power supply 5. Sensor damage 6. signal input interface fault on ECM				1. Plug again 2. Repair wire harness 3. Repair wire harness 4. Repair wire harness 5. Replace sensor 6. Replace ECM

Fault code	P0118		Coolant temperature sensor circuit high voltage or open circuit
Set up emergency control plan:			Turn on the fault lights until the fault is gone Start with air inlet temperature，Fixed after increasing to 79.5 degrees over time
Wire connection terminal:				MT62.1	Coolant temperature sensor		Normal measuring signal
Coolant temperature signal:				20	A		0.5～4.5V
Sensor signal ground				46	C		0V
Judging condition		Possible fault reasons				Referred failure troubleshooting
Engine running time﹥2 seconds CTS﹥135C fault duration time﹥2 seconds		1. Temperature signal circuit is short-circuited to earth 2. Sensor is damaged 3. Pressure signal input interface fault on ECM				1. Repair wire harness 2. Replace sensor 3. Replace ECM

Fault code	P0122		ETC throttle valve position sensor１＃circuit low voltage
Set up emergency control plan:			Turn on the fault lights until the fault is gone Idle ，set throttle valve position sensor opening 0%；other opening changes with rotating speed throttle valve position sensor auto-zero function stops clear function stops
Wire connection terminal:				MT62.1	Throttle valve position sensor		Normal measuring signal
5V reference voltage:				39	A		5V
Throttle valve position 1 signal:				14	D		0.5～4.5V
Sensor signal ground				45	F		0V
Judging condition		Possible fault reasons				Referred failure troubleshooting
Engine running，rotate speed﹤3000rpm no MAP fault，and MAP﹤70kpa fault duration time﹥2秒		1. sensor signal circuit is short-circuited to to power positive pole or reference voltage circuit 2. Sensor is damaged 3. Pressure signal input interface fault on ECM				1. Repair wire harness 2. Replace sensor 3. Replace ECM

Fault code	P0123		ETC throttle valve position sensor 1＃ circuit high voltage or open circuit
Set up emergency control plan:			Turn on the fault lights until the fault is gone Idle ，set throttle valve position sensor opening 0%；other opening changes with rotating speed throttle valve position sensor auto-zero function stops clear function stops
Wire connection terminal:				MT62.1	Throttle valve position sensor		Normal measuring signal
5V reference voltage:				39	A		5V
Throttle valve position 1 signal:				14	D		0.5～4.5V
Sensor signal ground				45	F		0V
Judging condition		Possible fault reasons				Referred failure troubleshooting
duration time﹥2 seconds		1. The connector is not solid 2. sensor signal circuit open 3. Sensor signal has short circuit to ground 4. Sensor damage 5. signal input interface fault on ECM				1. Plug again 2. Repair wire harness 3. Repair wire harness 4. Replace sensor 5. Replace ECM

Fault code	P0131		Front oxygen sensor short circuit to low voltage
Set up emergency control plan:			Turn on the fault lights until the fault is gone and turn off the ignition switch System closed - loop working time delayed
Wire connection terminal:				MT62.1	Heating oxygen sensor		Normal measuring signal
System main power:				\	D		12V
Heating Drive:				41	C		0V
oxygen sensor high signal:				22	B		0～1000mV fluctuation
oxygen sensor low signal:				46	A		0V
Judging condition		Possible fault reasons				Referred failure troubleshooting
duration time﹥1 seconds		1. The heating drive circuit is short-circuited to the positive pole of the power supply 2. Sensor is damaged 3. Pressure signal input interface fault on ECM				1. Repair wire harness 2. Replace sensor 3. Replace ECM

Fault code	P0132		Front oxygen sensor short circuit to high voltage
Set up emergency control plan:			Turn on the fault lights until the fault is gone and turn off the ignition switch System closed - loop working time delayed
Wire connection terminal:				MT62.1	Heating oxygen sensor		Normal measuring signal
System main power:				\	D		12V
Heating Drive:				41	C		0V
oxygen sensor high signal:				22	B		0～1000mV fluctuation
oxygen sensor low signal:				46	A		0V
Judging condition		Possible fault reasons				Referred failure troubleshooting
No main relay failure duration time﹥1 seconds		1. The connector is not solid 2. The heating drives the circuit open 3. Heat drive line to ground short circuit 4. Sensor damage 5. signal input interface fault on ECM				1. Plug again 2. Repair wire harness 3. Repair wire harness 4. Replace sensor 5. Replace ECM

Fault code	P0133		front oxygen sensor responds too slowly
Set up emergency control plan:			Turn on the fault lights until the fault is gone and turn off the ignition switch System closed - loop working time delayed
Wire connection terminal:				MT62.1	Heating oxygen sensor		Normal measuring signal
System main power:				\	D		12V
Heating Drive:				41	C		0V
oxygen sensor high signal:				22	B		0～1000mV fluctuation
oxygen sensor low signal:				46	A		0V
Judging condition		Possible fault reasons				Referred failure troubleshooting
No main relay failure duration time﹥1 seconds		1. The connector is not solid 2. The heating drives the circuit open 3. Heat drive line to ground short circuit 4. Sensor damage 5. signal input interface fault on ECM				1. Plug again 2. Repair wire harness 3. Repair wire harness 4. Replace sensor 5. Replace ECM

Fault code	P0137		Rear oxygen sensor short circuit to low voltage
Set up emergency control plan:			Turn on the fault lights until the fault is gone and turn off the ignition switch System closed - loop working time delayed
Wire connection terminal:				MT62.1	Heating oxygen sensor		Normal measuring signal
System main power:				\	D		12V
Heating Drive:				41	C		0V
oxygen sensor high signal:				22	B		0～1000mV fluctuation
oxygen sensor low signal:				46	A		0V
Judging condition		Possible fault reasons				Referred failure troubleshooting
duration time﹥1 seconds		1. The heating drive circuit is short-circuited to the positive pole of the power supply 2. Sensor is damaged 3. Pressure signal input interface fault on ECM				1. Repair wire harness 2. Replace sensor 3. Replace ECM

Fault code	P0138		Rear oxygen sensor short circuit to high voltage
Set up emergency control plan:			Turn on the fault lights until the fault is gone and turn off the ignition switch System closed - loop working time delayed
Wire connection terminal:				MT62.1	Heating oxygen sensor		Normal measuring signal
System main power:				\	D		12V
Heating Drive:				41	C		0V
oxygen sensor high signal:				22	B		0～1000mV fluctuation
oxygen sensor low signal:				46	A		0V
Judging condition		Possible fault reasons				Referred failure troubleshooting
No main relay failure duration time﹥1 seconds		1. The connector is not solid 2. The heating drives the circuit open 3. Heat drive line to ground short circuit 4. Sensor damage 5. signal input interface fault on ECM				1. Plug again 2. Repair wire harness 3. Repair wire harness 4. Replace sensor 5. Replace ECM

Fault code	P0222		ETC throttle valve position sensor 2＃circuit low voltage
Set up emergency control plan:			Turn on the fault lights until the fault is gone Idle ，set throttle valve position sensor opening 0%；other opening changes with rotating speed throttle valve position sensor auto-zero function stops clear function stops
Wire connection terminal:				MT62.1	Throttle valve position sensor		Normal measuring signal
5V reference voltage:				39	A		5V
Throttle valve position 2 signal:				16	E		0.5～4.5V
Sensor signal ground				45	F		0V
Judging condition		Possible fault reasons				Referred failure troubleshooting
Engine running，rotate speed﹤3000rpm no MAP fault，and MAP﹤70kpa fault duration time﹥2s		1. sensor signal circuit is short-circuited to power positive pole or reference voltage circuit 2. Sensor is damaged 3. Pressure signal input interface fault on ECM				1. Repair wire harness 2. Replace sensor 3. Replace ECM

Fault code	P0223		ETC throttle valve position sensor 2＃ circuit high voltage or open circuit
Set up emergency control plan:			Turn on the fault lights until the fault is gone Idle ，set throttle valve position sensor opening 0%；other opening changes with rotating speed throttle valve position sensor auto-zero function stops clear function stops
Wire connection terminal:				MT62.1	Throttle valve position sensor		Normal measuring signal
5V reference voltage:				39	A		5V
Throttle valve position 2 signal:				16	E		0.5～4.5V
Sensor signal ground				45	F		0V
Judging condition		Possible fault reasons				Referred failure troubleshooting
duration time﹥2 seconds		1. The connector is not solid 2. sensor signal circuit open 3. Sensor signal has short circuit to ground 4. Sensor damage 5. signal input interface fault on ECM				1. Plug again 2. Repair wire harness 3. Repair wire harness 4. Replace sensor 5. Replace ECM

Fault code	P0325		Knock sensor failure
Set up emergency control plan:			Turn on the fault lights until the ignition switch is off Adopt safe ignition advance angle table
Wire connection terminal:				MT62.1	knock sensor		Normal measuring signal
Knock signal high:				25			0-1V
Knock signal low:				37			0V
Judging condition		Possible fault reasons				Referred failure troubleshooting
Engine rotate speed﹥2000rpm MAP﹥50kPa fault duration time﹥5 seconds		1. The connector is not solid 2. The knock signal circuit open 3. Sensor signal ground short circuit 4. Knock signal other circuit short circuit 5. Sensor damage 6. Signal output interface fault on ECM				1. Plug again 2. Repair wire harness 3. Repair wire harness 4. Repair wire harness 5. Replace sensor 6. Replace ECM

Fault code	P0336		Crankshaft position sensor circuit signal interfere
Set up emergency control plan:			Turn on the fault lights until the fault is gone
Wire connection terminal:				MT62.1	Crankshaft position sensor		Normal measuring signal
Sensor signal :				33	A		〉400mV sine wave（with sensor B）
voltage signal:				38	C		〉400mV sine wave（with sensor A）
System ground wire:				46	B		0V
Judging condition		Possible fault reasons				Referred failure troubleshooting
Engine running The number of teeth entering ECM for 5 consecutive cycles is not equal to 58		1. The signal line is badly shielded 2. There are metal objects in the 58x gear ring				1. Use shield wire 2. Clean 58x gear ring

Fault code	P0337		Crankshaft position sensor circuit no signal
Set up emergency control plan:			Turn on the fault lights until the fault is gone the engine failed to start
Wire connection terminal:				MT62.1	Crankshaft position sensor		Normal measuring signal
Sensor signal :				33	A		〉400mV sine wave（with sensor B）
voltage signal:				38	C		〉400mV sine wave（with sensor A）
System ground wire:				46	B		0V
Judging condition		Possible fault reasons				Referred failure troubleshooting
Start engine No engine speed signal MAP reduces 2.9509kPa System voltage drops 0.8V speed<4km/h duration time﹥2 seconds		1. The connector is not solid 2. The signal is reversed high and low 3. Signal circuit open 4. Signal circuit other short circuit 5. Sensor damage 6. Signal input interface fault on ECM				1. Plug again 2. Repair wire harness 3. Repair wire harness 4. Repair wire harness 5. Replace sensor 6. Replace ECM

Fault code	P0341	Camshaft position sensor reasonable fault
Set up emergency control plan:		Turn on the fault lights until the fault is gone he injection sequence has a 50% chance of 360 degrees of dislocation
Wire connection terminal:			MT62.1	Camshaft position sensor		Normal measuring signal
5V reference voltage:			39	C		5V
Camshaft signal:			21	A		0-5V square wave
Sensor signal ground:			45	B		0V
Judging condition		Possible fault reasons			Referred failure troubleshooting
Engine running		1. The connector is not solid 2. reference voltage circuit open 3. signal ground open 4. Camshaft signal open 5. Sensor damage 6. interface fault on ECM			1. Plug again 2. Repair wire harness 3. Repair wire harness 4. Repair wire harness 5. Replace sensor 6. Replace ECM

Fault code	P0340		Camshaft position sensor no signal
Set up emergency control plan:			Turn on the fault lights until the fault is gone he injection sequence has a 50% chance of 360 degrees of dislocation
Wire connection terminal:				MT62.1	Camshaft position sensor		Normal measuring signal
5V reference voltage:				39	C		5V
Camshaft signal:				21	A		0-5V square wave
Sensor signal ground:				45	B		0V
Judging condition		Possible fault reasons				Referred failure troubleshooting
Engine running		1. The connector is not solid 2. reference voltage circuit open 3. signal ground open 4. Camshaft signal open 5. Sensor damage 6. interface fault on ECM				1. Plug again 2. Repair wire harness 3. Repair wire harness 4. Repair wire harness 5. Replace sensor 6. Replace ECM

Fault code	P0351		1# ignition coil malfunction
Set up emergency control plan:			Turn on the fault lights until the fault is gone Stop spraying oil on 1 cylinder The target idling is raised to 1200rpm
Wire connection terminal:				MT62.1	ignition coil		Normal measuring signal
System main power:				\			12V
1 cylinder drive:				04			0-12V approximate square wave signal induction peak〉300V
Judging condition		Possible fault reasons				Referred failure troubleshooting
duration time﹥1.25 seconds		1. 1 cylinder drive circuit and power positive short circuit 2. Ignition coil is damaged 3. ECM fault				1. Repair wire harness 2. Replace ignition coil 3. Replace ECM

Fault code	P0352		2# ignition coil malfunction
Set up emergency control plan:			Turn on the fault lights until the fault is gone Stop spraying oil on 1 cylinder The target idling is raised to 1200rpm
Wire connection terminal:				MT62.1	ignition coil		Normal measuring signal
System main power:				\			12V
2 cylinder drive:				81			0-12V approximate square wave signal induction peak〉300V
Judging condition		Possible fault reasons				Referred failure troubleshooting
duration time﹥1.25 seconds		1. 2 cylinder drive circuit and power positive short circuit 2. Ignition coil is damaged 3. ECM fault				1. Repair wire harness 2. Replace ignition coil 3. Replace ECM

Fault code	P0353		3# ignition coil malfunction
Set up emergency control plan:			Turn on the fault lights until the fault is gone Stop spraying oil on 1 cylinder The target idling is raised to 1200rpm
Wire connection terminal:				MT62.1	ignition coil		Normal measuring signal
System main power:				\			12V
3 cylinder drive:				01			0-12V approximate square wave signal induction peak〉300V
Judging condition		Possible fault reasons				Referred failure troubleshooting
duration time﹥1.25 seconds		1. 3 cylinder drive circuit and power positive short circuit 2. Ignition coil is damaged 3. ECM fault				1. Repair wire harness 2. Replace ignition coil 3. Replace ECM

Fault code	P0354		4# ignition coil malfunction
Set up emergency control plan:			Turn on the fault lights until the fault is gone Stop spraying oil on 1 cylinder The target idling is raised to 1200rpm
Wire connection terminal:				MT62.1	ignition coil		Normal measuring signal
System main power:				\			12V
4 cylinder drive:				62			0-12V approximate square wave signal induction peak〉300V
Judging condition		Possible fault reasons				Referred failure troubleshooting
duration time﹥1.25 seconds		1. 4 cylinder drive circuit and power positive short circuit 2. Ignition coil is damaged 3. ECM fault				1. Repair wire harness 2. Replace ignition coil 3. Replace ECM

Fault code	P0458		Carbon canister electromagnetic valve short circuit to low voltage
Set up emergency control plan:			Turn on the fault lights until the fault is gone close charcoal canister solenoid valve
Wire connection terminal:				MT62.1	Carbon canister solenoid valve		Normal measuring signal
System main power:				\	B		12V
Solenoid valve drive:				64	A		0-12V square wave
Judging condition		Possible fault reasons				Referred failure troubleshooting
duration time﹥2 seconds		1. Solenoid valve drive circuit has short circuit to the system power anode 2. Solenoid valve is damaged 3. ECM fault				1 .repair wire harness 2. Replace control valve 3. Replace ECM

Fault code	P0459		Carbon canister electromagnetic valve short circuit to high voltage
Set up emergency control plan:			Turn on the fault lights until the fault is gone close charcoal canister solenoid valve
Wire connection terminal:				MT62.1	Carbon canister solenoid valve		Normal measuring signal
System main power:				\	B		12V
Solenoid valve drive:				64	A		0-12V square wave
Judging condition		Possible fault reasons				Referred failure troubleshooting
duration time﹥5 seconds		1. The connector is not solid 2. Solenoid valve drive circuit has short circuit to the system power negative pole 3. Solenoid valve drive circuit open 4. the circuit connected with system main power circuit open 5. Solenoid valve damage 6. Fault on ECM				1. Plug again 2. Repair wire harness 3. Repair wire harness 4. Repair wire harness 5. Replace solenoid valve 6. Replace ECM

Fault code	P0480		Low speed fan failure
Set up emergency control plan:			Turn on the fault lights until the fault is gone Fan does not working（open circuit），The high speed fan starts and works constantly when the water temperature rises to 98 degrees（short circuit to ground）
Wire connection terminal:				MT62.1	Low speed fan relay		Normal measuring signal
Battery:				\	Instructions provided by car factory		12V
Relay drive:				65	Instructions provided by car factory		0V（working），12V（stopping）
Judging condition		Possible fault reasons				Referred failure troubleshooting
duration time﹥3 seconds		1. The connector is not solid 2. Relay drive circuit has short circuit to the system power negative pole 3. Relay drive circuit open 4. the circuit connected with battery open 5. Relay damage 6. fault on ECM				1. Plug again 2. Repair wire harness 3. Repair wire harness 4. Repair wire harness 5. Replace relay 6. Replace ECM

Fault code	P0562		System voltage is low
Set up emergency control plan:			Turn on the fault lights until the fault is gone The system stopped spraying oil
Wire connection terminal:				MT62.1	Ignition switch		Normal measuring signal
Ignition switch				68	Refer to electrical system instructions		12V
Judging condition		Possible fault reasons				Referred failure troubleshooting
Turn on ignition switch system voltage﹤7.6V duration time〉5seconds		1. The generator regulator is damaged 2. Wrong usage of low voltage battery				1.Replace the damaged generator regulator 2. Use correct battery

Fault code	P0563		System voltage is high
Set up emergency control plan:			Turn on the fault lights until the fault is gone The system stopped spraying oil
Wire connection terminal:				MT62.1	Ignition switch		Normal measuring signal
Ignition switch				68	Refer to electrical system instructions		12V
Judging condition		Possible fault reasons				Referred failure troubleshooting
Turn on ignition switch system voltage〉17.2V duration time〉5seconds		1. The generator regulator is damaged 2. Wrong usage of high voltage battery				1.Replace the damaged generator regulator 2. Use correct battery

Fault code	P2122	Electronic accelerator pedal position sensor 1# circuit low voltage or open circuit
Set up emergency control plan:		Turn on the fault lights until the fault is gone
Wire connection terminal:			MT62.1	Accelerator position sensor 1		Normal measuring signal
5V reference voltage:			70	2		5V
Accelerator pedal signal 1:			41	4		0.5～4.5V
Sensor signal ground:			74	3		0V
Judging condition		Possible fault reasons			Referred failure troubleshooting
Engine running failure duration time﹥2.5 seconds		1. Accelerator position sensor signal circuit is short-circuited to the 5V reference voltage or power positive pole 2. Sensor is damaged 3. Pressure signal input interface fault on ECM			1. Repair wire harness 2. Replace sensor 3. Replace ECM

Fault code	P2123	Electronic accelerator pedal position sensor 1# circuit high voltage
Set up emergency control plan:		Turn on the fault lights until the fault is gone
Wire connection terminal:			MT62.1	Accelerator position sensor 1		Normal measuring signal
5V reference voltage:			70	2		5V
Accelerator pedal signal 1:			41	4		0.5～4.5V
Sensor signal ground:			74	3		0V
Judging condition		Possible fault reasons			Referred failure troubleshooting
Engine running failure duration time﹥2.5 seconds		1. The connector is not solid 2. sensor signal circuit open 3. Sensor signal has short circuit to ground 4. Sensor damage 5. signal input interface fault on ECM			1. Plug again 2. Repair wire harness 3. Repair wire harness 4. Replace sensor 5. Replace ECM

Fault code	P2127	Electronic accelerator pedal position sensor 2# circuit low voltage or open circuit
Set up emergency control plan:		Turn on the fault lights until the fault is gone
Wire connection terminal:			MT62.1	Accelerator position sensor 2		Normal measuring signal
5V reference voltage:			66	1		5V
Accelerator pedal signal 2:			42	6		0.5～4.5V
Sensor signal ground:			76	5		0V
Judging condition		Possible fault reasons			Referred failure troubleshooting
Engine running failure duration time﹥2.5 seconds		1. Accelerator position sensor signal circuit is short-circuited to the 5V reference voltage or power positive pole 2. Sensor is damaged 3. Pressure signal input interface fault on ECM			1. Repair wire harness 2. Replace sensor 3. Replace ECM

Countersign
Approve	Checking	Proofread	Compile

Fault phenomena	possible causes	solution
Engine can not be started or starts hard	Ignition coil or switch fault	Check or replace ignition coil or switch fault
	spark plug fault	Check and replace spark plug
	The high-voltage line is disconnected or not connected	Check high voltage line
Engine idling unstable	High pressure wire or spark plug malfunction	Check High pressure wire or check and replace spark plug
Engine idling unstable	ignition coil malfunction	Check or replace ignition coil
The engine is wheezing or weak in acceleration	high voltage line malfunction	Check or replace high voltage line
The engine is wheezing or weak in acceleration	spark plug fault	Check and replace spark plug
fuel economy is poor	spark plug fault	Check and replace spark plug

ignition coil	primary coil resistance	0.77～0.95Ω
spark plug	sparking plug gap	0.7～0.8mm