Air Bag Systems: Service and Repair

Proper diagnosis and testing of the airbag system components, the PCI data bus, the data bus message inputs to and outputs from the Electro-Mechanical Instrument Cluster (EMIC) or the Airbag Control Module (ACM), as well as the retrieval or erasure of a Diagnostic 'Trouble Code (DTC) from the ACM requires the use of a DRB III scan tool. Refer to the appropriate diagnostic information.

WARNING: ON VEHICLES EQUIPPED WITH AIRBAGS, DISABLE THE AIRBAG SYSTEM BEFORE ATTEMPTING ANY STEERING WHEEL, STEERING COLUMN, OR INSTRUMENT PANEL COMPONENT DIAGNOSIS OR SERVICE. DISCONNECT AND ISOLATE THE BATTERY NEGATIVE (GROUND) CABLE, THEN WAIT TWO MINUTES FOR THE AIRBAG SYSTEM CAPACITOR TO DISCHARGE BEFORE PERFORMING FURTHER DIAGNOSIS OR SERVICE. THIS IS THE ONLY SURE WAY TO DISABLE THE AIRBAG SYSTEM. FAILURE TO TAKE THE PROPER PRECAUTIONS COULD RESULT IN ACCIDENTAL AIRBAG DEPLOYMENT AND POSSIBLE PERSONAL INJURY.

Standard Procedure - Handling Of Non-deployed Airbags
At no time should any source of electricity be permitted near the inflator on the back of a non-deployed airbag. When carrying a non-deployed airbag, the trim cover or airbag cushion side of the unit should be pointed away from the body to minimize injury in the event of an accidental deployment. If the airbag unit is placed on a bench or any other surface, the trim cover or airbag cushion side of the unit should be face up to minimize movement in the event of an accidental deployment. In addition, the airbag system should be disarmed whenever any steering wheel, steering column, or instrument panel components require diagnosis or service. Failure to observe this warning could result in accidental airbag deployment and possible personal injury.

All damaged or faulty and non-deployed driver or passenger airbags which are replaced on vehicles are to be returned. If an airbag unit is faulty or damaged and non-deployed, refer to the parts return list in the current Daimler Chrysler Corporation Warranty Policies and Procedures for the proper handling and disposal procedures.

Air Storage
An airbag must be stored in its original, special container until it is used for service. Also, it must be stored in a clean, dry environment; away from sources of extreme heat, sparks, and high electrical energy. Always place or store any airbag on a surface with its trim cover or airbag cushion side facing up, to minimize movement in case of an accidental deployment.

Standard Procedure - Verification Test
The following procedure should be performed using a DRB III scan tool to verify proper airbag system operation following the service or replacement of any airbag system component.

WARNING: ON VEHICLES EQUIPPED WITH AIRBAGS, DISABLE THE AIRBAG SYSTEM BEFORE ATTEMPTING ANY STEERING WHEEL, STEERING COLUMN, OR INSTRUMENT PANEL COMPONENT DIAGNOSIS OR SERVICE. DISCONNECT AND ISOLATE THE BATTERY NEGATIVE (GROUND) CABLE, THEN WAIT TWO MINUTES FOR THE AIRBAG SYSTEM CAPACITOR TO DISCHARGE BEFORE PERFORMING FURTHER DIAGNOSIS OR SERVICE. THIS IS THE ONLY SURE WAY TO DISABLE THE AIRBAG SYSTEM. FAILURE TO TAKE THE PROPER PRECAUTIONS COULD RESULT IN ACCIDENTAL AIRBAG DEPLOYMENT AND POSSIBLE PERSONAL INJURY.

1. During the following test, the battery negative cable remains disconnected and isolated, as it was during the airbag component removal and installation procedures.

Fig.4 16-Way Data Link Connector - Typical:

2. Be certain that the DRB III scan tool contains the latest version of the proper DRB III software. Connect the DRB III to the 16-way Data Link Connector (DLC). The DLC is located on the driver side lower edge of the instrument panel, outboard of the steering column.
3. Turn the ignition switch to the ON position and exit the vehicle with the DRB III.
4. Check to be certain that nobody is in the vehicle, then reconnect the battery negative cable.
5. Using the DRB III, read and record the active (current) Diagnostic Trouble Code (DTC) data.
6. Next, use the DRB III to read and record any stored (historical) DTC data.
7. If any DTC is found in Step 5 or Step 6, refer to the appropriate diagnostic information.
8. Use the DRB III to erase the stored DTC data. If any problems remain, the stored DTC data will not erase. Refer to the appropriate diagnostic information to diagnose any stored DTC that will not erase. If the stored DTC information is successfully erased, go to Step 9.
9. Turn the ignition switch to the OFF position for about fifteen seconds, and then back to the ON position. Observe the airbag indicator in the instrument cluster. It should light for six to eight seconds, and then go out. This indicates that the airbag system is functioning normally and that the repairs are complete. If the airbag indicator fails to light, or lights and stays ON, there is still an active airbag system fault or malfunction. Refer to the appropriate diagnostic information to diagnose the problem.

For addtional testing please refer to Powertrain Management/Computers and Controls/Body Control Module/Testing and Inspection/ Testing and Inspection