SRS System
Precaution for Technicians Using Medical Electric
Key Part Check before Maintenance and Repair
Precaution for Technicians Using Medical Electric
Operation Prohibition
Warning：
Parts with strong magnet is used in this vehicle.
Technicians using a medical electric device such as pacemaker must never perform operation on the vehicle, as magnetic field can affect the device function by approaching to such parts.
Normal charge precaution
Warning：
If a technician uses a medical electric device such as an implantable cardiac pacemaker or an implantable cardioverter defibrillator, the possible effects on the devices must be checked with the device manufacturer before starting the charge operation.
As radiated electromagnetic wave generated by on board charger at normal charge operation may affect medical electric devices, a technician using a medical electric device such as implantable cardiac pacemaker or an implantable cardioverter defibrillator must not enter the vehicle compartment (including trunk) during normal charge operation.
Precaution at telematics system operation
If a technician uses implantable cardiac pacemaker or implantable cardioverter defibrillator (ICD), avoid the device implanted part from Communication device.
The electromagnetic wave of TCU might affect the function of the implantable cardiac pacemaker or the implantable cardioverter defibrillator (ICD), when using the service, etc.
If a technician uses other medical electric devices than implantable cardiac pacemaker or implantable cardioverter defibrillator (ICD), the electromagnetic wave of TCU might affect the function of the device. The possible effects on the devices must be checked with the device manufacturer before TCU use.
Key Part Check before Maintenance and Repair
Check the high-voltage system, and ensure the high-voltage system is powered off before starting the maintenance work, and disconnect the battery switch.
Cautions
Warning：
During repair, if you do not conduct the operation according to correct procedure, it may lead to accidental explosion as airbag system has been repaired and result in serious accidents.
The mistakes in the process of repairing may lead to accidental explosion as airbag has been repaired and result in serious accidents.
Before conducting repair(including removal. installation. test or replacement of components and parts), please read the following instructions carefully and conduct operation according to regulated correct procedure in the service manual.
Individuals are not permitted to remove airbag system, removal operation should be conducted by professional staff.
1. Do not decompose the driver air bag and the passenger air bag assemblies and the SRS components.
2. Never repair any of the following component parts, only use replacement parts to replace these component parts.
1) SRS fitted on the driver side.
2) SRS fitted on the passenger side.
3) SRS Control Module.
3. Never expose the air bag to high temperature or fire.
4. If the air bag has contact with grease. detergent. oil. or water, please use dry rag to wipe it off.
5. Never make the air bag drop. Never use the air bag if it has been dropped.
6. Only get the original replacement parts from JAC authorized distributor.
7. After removing the SRS, make the front face up and put it in the smooth place. Do not put any articles on the front.
8. Verify whether the replacement parts numbers are right or not. Do not use the parts of other vehicles as substitutes.
9. Even though under the condition that the air bag was not ignited in the slight collision accident, the gasket surface and the air bag sensor should be inspected. If the dent. crack or deformation was found, install the new air bag assembly.
10. When abandoning the vehicle or the air bag, please dispose the air bag firstly.
11. After the air bag ignition, the inflatable device will become pretty hot, dispose the inflatable device after it experiences the natural cooling. Do not cool down it by water.
12. Measuring the circuit resistance of the air bag module is forbidden, which will lead to air bag ignition.
Preparations
Commonly used service and special tools are in need during the maintenance and repair.
Special Tool Diagram
|
Tools |
Diagram |
Function |
|
Ignition Tools |
|
Ignite the air bag |
|
Diagnosis Inspector |
|
Module Harness Inspector |
|
Simulator |
|
Check the simulator connector of the harness resistance |
Generally speaking, the SRS system is the air bag system, the “SRS” identification will be found on the trim cover of the air bag or the places where being the air bags;
1. Driver Airbag (Driver Airbag-DAB): When the front collision happening, the air bag will protect the driver’s upper torso, in some degree, it will protect the driver from moving forward. The air bag is installed into the steering wheel commonly, the trim cover of the DAB is actually the horn cover on the steering wheel;
2. Passenger Airbag (Passenger Airbag-PAB): When the severe front collision happening, the airbag will protect the passenger’s upper torso directly, in some degree, it will protect the passenger from moving forward. The airbag is installed into the instrument panel on the passenger side commonly, which can be divided into visible or hidden type;
3. Side Airbag（Side Airbag - SAB) ：The main function of side airbag is to provide extra protection for front driver. passenger. The protection parts include the breasts of front passengers and their hips as vehicle collision happened.
Cautions：
When driving the vehicle, please buckle up the seat belt according to requirement. The protective effect of the air bag used separately is not very obvious, and in a sense, if the air bag does not cooperate with the main restraint system (seat belt), it will lead severity of damage to the passenger. The air bag is the auxiliary device for the seat belt, not the replacement device for the seat belt.
1. Conditions of Airbag Deployment
Collision Angle Diagram that may lead to airbag deployment
The frontal collision with enough impact force that deviates from vehicle center line within 30 degrees may result in airbag deployment.
2. Position Diagram of Airbag System Components
Position Diagram of Airbag Components
|
1-Driver Side Airbag |
2-Passenger Side Airbag |
3-Position of Airbag Control Module |
3. Action Principle of Airbag System
When the collision accident happens to the vehicle, the collision between the vehicle and the obstacles called primary collision, the result of the primary collision is that the vehicle speed decreases rapidly; the collision between the occupants and the vehicle interior structure called secondary collision. Before the secondary collision happens between the occupants and the vehicle interior structure, insert a gas-filled air bag between the occupants and the vehicle interior structure quickly, the air bag will absorb the kinetic energy from the occupants through the air permeability itself and the exhaust throttle function of the deflation hole, which decreases the violent collision and isolates occupants and interior structure, finally reaches the aim to protect the occupants.
The air bag. seat and seat belt are made up of the vehicle restraint system.
Schematic Diagram of Restraint System Action
Driver SRS Assembly
|
1. Component Driver airbag assembly is located in steering wheel.
|
|
Caution：
Place the driver air bag module with gasket side facing upward when removing the driver air bag assembly or installing a new driver air bag assembly.
Do not measure the air bag resistance, which may lead to igniting the air bag accidentally.
Place the driver air bag in the right place, where the environmental temperature is under 80℃, and is away from electric noise.
When electric welding is conducted, always disconnect the storage battery negative terminal and the air bag connectors.
When the vehicle or the air bag is discarded, please use special tools to ignite the air bag.
2. Removal Steps
1) Before removal, disconnect the storage battery negative terminal and wait for more than 3 minutes.
2) Schematic Diagram of DAB Removal (three steps), use the straight screwdriver with the length of 15cm as the removal tool.
a. Remove the demounting holes of 3H：use screwdriver to pierce the mounting and dismounting holes on the steering wheel, stir the snap on the steering wheel, separate the snap joint from the steering wheel frame.
b. Remove the demounting holes of 6H：use screwdriver to pierce the mounting and dismounting holes on the steering wheel, stir the snap on the steering wheel, separate the snap joint from the steering wheel frame.
c. Remove the demounting holes of 9H：use screwdriver to pierce the mounting and dismounting holes on the steering wheel, stir the snap on the steering wheel, separate the snap joint from the steering wheel frame.
|
|
Enlarged View of the Demounting Hole |
|
|
|
|
3) Disconnect the connectors, pull out the air bag module. 4) Place the air bag module properly according to therequirements. The correct placement is shown as the right figure. |
Placement Diagram of Driver Airbag |
|
4. Installation Steps Assemble in the reverse step of removal.
|
|
|
1. Component Parts Diagram The co-pilot SRC assembly is embedded in the interior instrument panel on the co-pilot side. |
Location Diagram of the co-pilot SRC Assembly Installation |
Cautions：
Do not place or post any items on the air bag surface.
Please refer to the precautions for “Driver SRC Assembly”.
2. Removal
1) Before removal, disconnect the storage battery negative terminal and wait for more than 3 minutes.
2) Remove the glove compartment
3) Remove the mounting bolts of the passenger air bag on the instrument panel tubular beam.
4) Use flat head screwdriver to pry off airbag cover.
5) Disconnect the connector, take down the airbag from airbag box in the instrument panel.
Turn the cover upward and place the airbag.
2. Installation
Assemble in the reverse step of removal.
Air Bag Control Unit (ACU)
1. Function of the Air Bag Control Unit (ACU)
1) Induct the vehicle collision.
2) Ignite the driver and passenger air bags.
3) Ignite the pre-tensioning seat belt on the driver and passenger side.
4) Monitor the working conditions of Air Bag system.
5) Inform the driver of the air bag system state through warning indicator lamp: ready or faulted.
6) Diagnose and maintain the air bag system through serial diagnosis communication port.
7) After collision, record the relevant collision information data and working states of all the air bag system components.
8) After collision, transfer the collision signal to ETACS module. Engine ECU module. ETACS module opens the locked door, which is convenient for the occupants to escape; the Engine ECU module disconnects oil circuit to prevent the fire.
2. Air Bag Control Module (ACU) Pin
Terminal Diagram of ACU and Specified Content of Relevant Pin as shown in the following list
Terminal Diagram of ACU
|
Pin |
Pin Designation |
Pin Description |
Terminal |
4 Loops |
|
1 |
DBT+ |
Driver Seat Belt Pretensioning Positive |
Gold |
X |
|
2 |
DBT- |
Driver Seat Belt Pretensioning Negative |
Gold |
X |
|
3 |
PBT+ |
Copilit Seat Belt Pretensioning Positive |
Gold |
X |
|
4 |
PBT- |
Copilit Seat Belt Pretensioning Negative |
Gold |
X |
|
5 |
Vbat |
Power Supply Positive |
Gold |
X |
|
6 |
GND |
Grounding |
Gold |
X |
|
7 |
W/L |
Malfunction Indicator Lamp |
Gold |
X |
|
8 |
NA |
Unused |
Gold |
0 |
|
y |
K_Line |
Diagnosis Interface |
Gold |
X |
|
10 |
DFAB+ |
Driver Frontal Airbag Positive |
Gold |
X |
|
11 |
DFAB- |
Driver Frontal Airbag Negative |
Gold |
X |
|
12 |
CRO2 |
Collision Output 2 |
Gold |
X |
|
13 |
PFAB+ |
Copilot Frontal Airbag Positive |
Gold |
X |
|
14 |
PFAB- |
Copilot Frontal Airbag Negative |
Gold |
X |
|
15 |
NA |
Unused |
Gold |
0 |
|
16 |
NA |
Unused |
Gold |
0 |
|
17 |
NA |
Unused |
Gold |
0 |
|
18 |
NA |
Unused |
Gold |
0 |
|
19 |
NA |
Unused |
Gold |
0 |
|
20 |
NA |
Unused |
Gold |
0 |
|
21 |
NA |
Unused |
Gold |
0 |
|
22 |
NA |
Unused |
Gold |
0 |
|
23 |
NA |
Unused |
Gold |
0 |
|
24 |
NA |
Unused |
Gold |
0 |
|
25 |
NA |
Unused |
Gold |
0 |
|
26-27 |
SBO |
Short-Circuit |
|
X |
|
28-29 |
SBO |
Short-Circuit |
|
X |
|
30 |
NA |
Unused |
Gold |
0 |
|
31-32 |
SBO |
Short-Circuit |
|
X |
|
33 |
NA |
Unused |
Gold |
0 |
|
34 |
NA |
Unused |
Gold |
0 |
|
35-36 |
SBO |
Short-Circuit |
|
X |
|
37 |
CRO1 |
碰撞输出1 |
Gold |
X |
|
38-39 |
SBO |
Short-Circuit |
|
X |
|
40 |
NA |
Unused |
Gold |
0 |
|
41-42 |
SBO |
Short-Circuit |
|
X |
|
43-44 |
SBO |
Short-Circuit |
|
X |
|
45 |
NA |
Unused |
Gold |
0 |
|
46 |
NA |
Unused |
Gold |
0 |
|
47 |
NA |
Unused |
Gold |
0 |
|
48 |
NA |
Unused |
Gold |
0 |
|
49 |
NA |
Unused |
Gold |
0 |
|
50 |
NA |
Unused |
Gold |
0 |
Definition table of ACU pin
3. Removal of Air Bag Control Unit (ACU)
1) Turn off the ignition switch, disconnect the storage battery negative terminal, wait for 3 or more minutes until the complete discharge of interior capacitive storage of ACU.
2) Remove the vice instrument panel(see Removal and Installation of Vice Instrument Panel).
3) Remove the three mounting bolts of ACU, loosen and pull the harness connector of ACU, pull out the ACU.
Cautions：
Never make the ACU drop or suffer from an impact.
4. Air Bag Control Unit（ACU)
Install in the reverse step of removal
Cautions：
Please pay attention to the direction of ACU when installing, make sure that the arrows labeled on ACU should be aligned with the vehicle driving direction.
SRS System Diagnosis
Turn the ignition switch to “ON” position, the air bag indicator lamp on the instrument panel will go out after flickering for a few seconds, which indicates that the air bag system stays in normal working state. After turning the ignition switch to “ON” position, the air bag indicator lamp will be off or always on, which indicates that the air bag system is faulted. In order to verify the malfunction reason further, the special malfunction diagnosis instrument should be used.
1) Use the diagnosis instrument to read out the malfunction code.
2) According to reminder from the malfunction code, carry out the maintenance.
3) Use the diagnosis instrument to eliminate the malfunction code.
Cautions：
After troubleshooting the malfunction, use diagnosis instrument to eliminate the malfunction code stored in the system.
Except the explained operations in the manual, the electrical testing equipment is forbidden to be used to test any circuits of the SRS system. Do not try to repair. connect or change SRS harness, if the harness is damaged, replace the harness. The grounding position should be kept clean.
1. If the air bag is not ignited under the condition that the vehicle crash under lower speed. side collision. rollover. rear-end collision, inspect the following items:
Check the ACU body and mounting bracket for dent. crack or deformation.
Check the connector for damage and check the terminal for deformation.
Check the mounting bolt. grounding wires for damage.
2. SRS System Maintenance and Inspection
1) SRS Module
① Check the gasket cover for dent. crack or deformation.
② Check the connector for damage. the terminal for deformation and wiring harness for seizure.
③ Check the gas generator body of air bag for dent. crack or deformation.
④ Install the SRS components to the steering wheel, check the components for cooperation with the steering wheel or alignment state.
2) Warning/Visible Labels
A mass of warning/visible labels in regard to SRS have been printed on the vehicle.
On the steering wheel frame.
On the driver air bag module.
On the passenger air bag module.
On the air bag control module(ACU).
Please obey the instructions on the labels when servicing the SRS. Replace them if the labels are smudged or damaged.
3) Air Bag Control Unit(ACU)
If the ACU malfunctions, never repair it, please replace a new one.
Before discarding the SRS or the vehicle equipped with SRS, ignite the SRS, without permission, any individual shall not be allowed to ignite the SRS, please hand it to professional to ignite the SRS.