Diagnosis And Testing
To avoid serious or fatal injury on vehicles equipped with airbags, disable the Supplemental Restraint System (SRS) before attempting any steering wheel, steering column, airbag, seat belt tensioner, impact sensor or instrument panel component diagnosis or service. Disconnect and isolate the battery negative (ground) cable, then wait two minutes for the system capacitor to discharge before performing further diagnosis or service. This is the only sure way to disable the SRS. Failure to take the proper precautions could result in accidental airbag deployment.
SENSOR DIAGNOSIS
The Occupant Restraint Controller (ORC) will set DTCs when a sensor fault is detected. The sensors cannot be tested and are diagnosed by the process of elimination. After disconnecting the harness from the ORC and the sensor, the sensor circuits are checked for shorts to voltage or ground, sensor circuits shorted together, and wire resistance. Only after eliminating all possible circuit faults is the sensor replaced.
SQUIB DIAGNOSIS
The ORC will set DTCs when a squib concern is detected. The squibs cannot be tested and are diagnosed by the process of elimination. Squib circuits are tested using special SRS equipment.
The hardwired circuits between modules and components related to the Supplemental Restraint System (SRS) may be diagnosed using conventional diagnostic tools and procedures. Refer to the appropriate wiring information. The wiring information includes wiring diagrams, details of wire harness routing and retention, connector pin-out information and location views for the various wire harness connectors, splices and grounds. For proper wire repair, and connector repair procedures. Refer to STANDARD PROCEDURE and REMOVAL or INSTALLATION .
However, conventional diagnostic methods will not prove conclusive in the diagnosis of the SRS or the electronic controls and communication between other modules and devices that provide features of the SRS. The most reliable, efficient and accurate means to diagnose the SRS or the electronic controls and communication related to SRS operation, as well as the retrieval or erasure of a DTC requires the use of a diagnostic scan tool. Refer to the appropriate diagnostic information.
In addition to a diagnostic scan tool that contains the latest version of the proper diagnostic software, certain diagnostic procedures for the SRS may require the use of the Airbag Kit. Refer to the appropriate diagnostic information.