Special tool
 | Simulator, airbag - Driver airbag (Vehicles manufactured before 09/2002) 418-037 (40-001) |
 | Simulator, airbag - Driver airbag (Vehicles manufactured from 09/2002) 501-073 (40-016) |
 | Simulator, Airbag - Side airbag and seat belt buckle tensioner (Vehicles manufactured before 09/2002) 418-138 (40-010) |
 | Simulator, airbag - Side airbag and seat belt buckle tensioner (Vehicles produced from 09/2002) 501-093 (40-022) |
 | Simulator, airbag - Passenger airbag 418-139 (40-011) |
 | Wire for testing and deploying airbag/pyrotechnic seat belt pretensioner 418-S055 (40-007A) |
General equipment: WDS system.
Diagnosing customer complaints without hard DTC/LFC codes
WARNING: Before performing any work on the secondary restraint system and its associated components, the backup battery must be discharged. Failure to follow this instruction may result in personal injury.
NOTE: Performing pinpoint tests in the absence of diagnostic trouble codes/light warning lamp codes (DTCs/LFCs) will result in unnecessary air bag component replacements and repeat repairs.
Ask the customer if a specific set of conditions are required for the fault to manifest. If the customer reports an LFC, but the code is not present when the vehicle is brought in for repair, pinpoint diagnostics cannot be used. Instruct the customer on how to count LFCs.
Diagnostics of complaints received from the customer with "hard" DTC/LFC codes
WARNING: Do not use dummy air bags when performing work on the supplemental restraint system. Use only the appropriate tool. Failure to follow these instructions may result in personal injury.
Most air bag system diagnostic procedures require the use of system deactivation and system reactivation procedures. These procedures require disconnecting the air bag module(s) and seat belt pretensioners from the SRS, eliminating the risk of air bag deployment while the diagnostic procedure is being performed.
Airbag simulators are required to perform diagnostics and testing of the airbag system. Do not short the airbag module connections with a 0 ohm jumper wire. If a 0 ohm jumper wire is used to short the airbag module connections, an LFC will be set and the airbag control module will set a DTC.
Deactivation
WARNING: Before performing any work on the secondary restraint system, the backup power source must be discharged. Wait at least one minute after disconnecting the battery ground cable. Failure to follow this instruction may result in personal injury.
1. Disconnect the battery ground cable. For additional information, refer to Section 414-01.
2. Wait at least one minute for the energy stored in the air bag control module backup power source to discharge.
WARNING: Place the air bag module(s) on a grounded work bench with the trim cover facing up. Failure to follow this instruction could result in personal injury.
3. Remove the driver airbag module from the vehicle. For more information, refer to Driver Airbag Module in this section.
NOTE: Vehicles built before 10/2001: Install 418-037. Vehicles built since 10/2001: Install 501-073.
4. Connect the driver airbag simulator to the auxiliary wiring harness in place of the driver airbag module at the top of the steering column.
5. Disconnect the passenger air bag module electrical connector(s). For additional information, refer to Passenger Air Bag Module in this section.
6. Connect the passenger airbag simulator to the wiring harness in place of the passenger airbag module.
7. Disconnect the electrical connector of the wiring harness located on the floor under the driver's seat.
8. Instead of the side airbag module and seat belt pretensioner, connect the airbag simulator to the electrical connector of the wiring harness located on the floor under the driver's seat.
9. Disconnect the electrical connector of the wiring harness located on the floor under the passenger seat.
NOTE: Vehicles built before 10/2001: Install 418-138. Vehicles built since 10/2001: Install 501-093.
10. Instead of the side airbag and seat belt tensioner, connect a dummy airbag to the electrical connector of the wiring harness located on the floor under the passenger seat.
11. Connect the battery ground cable. Refer to Section 414-01 for additional information.
Reactivation
WARNING: When reactivating, the airbag simulators must be removed and the airbag modules must be reconnected to prevent the airbags from deploying in the event of a collision. Failure to follow this instruction may result in injury.
1. Disconnect the battery ground cable. For additional information, refer to Section 414-01.
2. Wait at least one minute for the energy stored in the air bag control module backup power source to discharge.
3. Remove the driver airbag simulator from the wiring harness at the top of the steering column.
4. Connect and install the driver airbag module. For more information, refer to Driver Airbag Module in this section.
5. Remove the passenger airbag simulator from the passenger airbag wiring harness.
6. Connect and install the passenger air bag module. For more information, refer to Passenger Air Bag Module in this section.
7. Remove the airbag simulator from the electrical connector on the wiring harness located under the driver's seat.
8. Connect the electrical connector of the wiring harness located under the driver's seat.
9. Remove the airbag simulator from the electrical connector on the wiring harness located under the passenger seat.
10. Connect the electrical connector of the wiring harness located under the passenger seat.
11. Connect the ground cable to the battery. For additional information, refer to Section 414-01.
12. Check that the system is working correctly.
Glossary
Airbag Simulator
Airbag simulators are used to simulate the connections of an airbag module to a system.
Deactivate the system
To deactivate a system means to perform a deactivation procedure. REFER to the "Deactivation" section of this section.
Check that the system is working properly
The airbag indicator light comes on for approximately three seconds. If a fault is detected, the indicator light flashes the corresponding fault code.
Reactivate the system
To reactivate a system means to perform the reactivation procedure. REFER to the "Reactivation" section of this section.
Operating principles
Function of the Supplemental Restraint System (SRS)
The car is equipped with a sensitive system that operates on alternating current.
In the event of a significant full frontal or three-quarter frontal collision that exceeds a specified threshold, the driver and passenger front airbag(s) (if equipped) deploy.
In the event of a significant all-side collision, the force of which exceeds a preset threshold, the driver's or passenger's side airbag (if equipped) deploys. The airbag deployment occurs only in the event of a severe impact when the ignition key is in the RUN position.
Airbag control module
The airbag control module maintains full control of the entire system, providing continuous system checks and full diagnostic capabilities. Non-volatile memory stores fault codes that can be downloaded to the WDS via the data link connector (DLC).
In the event of a failure of the vehicle's electrical system during a crash, the air bag control module supplies sufficient auxiliary electrical power to deploy the air bag(s) for at least 150 ms. The air bag control module discharges the reserve electrical power within 60 seconds after the battery ground cable is disconnected. This ensures that the auxiliary restraint system remains operational.
The air bag control module contains electronic acceleration sensor(s) that measure longitudinal acceleration and lateral acceleration (in vehicles equipped with side air bags) and provide both signals to the microcontroller, where the signal strength is proportional to the measured acceleration. When both of these sensors register an impact the strength of which exceeds a predetermined threshold, the air bag control module initiates the air bag deployment circuit. The air bag control module also contains a protection sensor that unlocks the front air bags and seat belt pretensioners in the event of a frontal collision or only the seat belt pretensioners in the event of a rear collision. The protection sensor also prevents unintentional deployment of the air bags and seat belt pretensioners in the event of a malfunction in the electronic acceleration sensor(s).
Vehicles equipped with the telematics system have a communication link from the airbag control module to the telematics control module. If the airbags deploy, the telematics control module automatically sends an SOS signal. For more information, refer to Section 419-05.
Airbag Control Module Configuration - Ground Connection (Vehicles built from 09/2002)
The air bag harness connections are the same for LHD and RHD. The air bag control module is internally configured for either LHD or RHD. A ground connection on the configuration pin provides a signal that the air bag control module is configured for RHD. This ground connection is not present on LHD vehicles. The air bag control module continuously monitors this ground signal, and for an incorrect condition, the air bag control module sets a DTC.
Front Impact Sensor (Vehicles produced from 09/2002)
The front impact sensor contains an acceleration sensor, a filter, an amplifier, and a dedicated integrated circuit for signal transmission. The sensor is mounted on the hood latch panel. The front impact sensor sends a signal, the level of which is determined by the severity of the impact, to the air bag control module. The air bag control module compares the signal with the stored data and, if necessary, activates the front air bags and seat belt pretensioners.
Side impact sensor
Side impact sensors are mounted on the seat side on both sides of the vehicle to facilitate remote detection of side impacts. Each side impact sensor contains a microprocessor that processes signals from an accelerometer built into the sensor. In the event of a collision whose severity exceeds a predetermined threshold, the side impact sensor processes the side impact data and sends a request to deploy the air bag to the air bag control module. The air bag control module compares the received command with the data stored in memory and deploys the side air bag on the side on which the deployment command was initiated. The air bag control module maintains control of the side air bags.
Airbag warning light
The airbag indicator lamp is integrated into the instrument cluster together with the automatic disconnect detection (ADD) circuit. The airbag indicator lamp comes on for three seconds when the ignition is turned on. If the system self-test is successful, the indicator lamp goes out; if a fault is detected, the indicator lamp will flash the corresponding fault code.
The ADD circuit is provided to keep the air bag indicator lamp illuminated continuously if the air bag control module circuit is compromised due to loss of power or ground. The air bag control module mounting bolts are part of the ground circuit.
The SRS system can be diagnosed using the data link connector (DLC) and the WDS to determine the nature of the malfunction. Once the DTC has been determined, the appropriate corrective measures can be selected using the Symptom Table. For additional information, refer to the Diagnostic Instructions - Supplemental Restraint System (SRS) in this section.
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