Diagnostic Instructions
Air Bag and Safety Belt Pretensioner Supplemental Restraint System (SRS)
Diagnostic Instructions
The Symptom Chart can be used to help locate SRS concerns if no DTCs are retrieved and the listed symptoms are observed. Whether or not the listed symptoms are observed, always carry out the following:
1. Retrieve all DTCs stored in the RCM memory. Refer to Self Test/Continuous Memory and Clear DTCs.
2. Run the Self Test to determine what DTCs are currently being sensed by the RCM.
3. If on-demand DTCs are different than continuous memory DTCs, always repair the on-demand DTCs first.
A DTC can indicate several concerns. The DTCs are to assist in system diagnosis and are not to be considered definitive. Always refer to the pinpoint test corresponding to the DTC to determine where the concern lies and to repair the concern correctly.
Self Test/On-Demand
The Self Test option is used to verify that no electrical concerns exist with the SRS. Upon entering the self-test, the RCM will make an electrical check of each electrical component in the system. If a concern is detected, a DTC is displayed on the scan tool with a brief description of the DTC. The self-test should always be run after any repair to verify that the repair was successful.
To run the on-demand Self Test, follow these steps:
1. Connect the scan tool to the DLC.
2. Turn the ignition switch to the ON position.
3. Follow the manufacturer's instructions for the scan tool being used.
4. Select RCM.
5. Select Self Test.
6. The module will run the self-test and display on-demand (reflecting hard system concerns) and continuous memory (historic) DTCs on the scan tool.
Self Test/Continuous Memory and Clear DTCs
During vehicle operation, the RCM will detect and store both intermittent and hard failure DTCs in non-volatile memory. The DTC strategy employed by the RCM incorporates a time-out scheme for determining when a concern exists in the system. This requires a concern to exist for up to one minute in the system before the RCM will detect it. For the RCM to determine that a concern no longer exists, the concern must be absent for up to one minute. The actual detection time-outs vary with each DTC. DTCs can be retrieved with a scan tool using the Self Test option. All DTCs stored in the RCM will be displayed on the scan tool along with a brief description of the DTC. If no DTCs are present, the scan tool will display a SYSTEM PASSED message. This option can also be used to clear DTCs from the RCM memory, as long as the concern no longer exists.
Once 75 hours of operation have been recorded by the RCM since the concern was last detected, all RCM continuous memory DTCs will automatically be removed from memory.
To retrieve or clear DTCs, follow these steps:
1. Connect the scan tool to the DLC.
2. Turn the ignition switch to the ON position.
3. Follow the manufacturer's instructions for the scan tool being used.
4. Select RCM.
5. Select Self Test.
6. NOTE: Before proceeding with the clearing operation, make note of the DTCs displayed. Once cleared, DTCs cannot be retrieved.
All DTCs will be displayed on the screen.
7. Clear the DTCs. After clearing the DTCs, cycle the key OFF, then ON.
- Continuous memory DTCs that have been cleared will not reoccur as "continuous memory" in the same key cycle. Only new DTCs which were not present before clearing can occur as "continuous memory" after clearing.