Reading and Clearing Diagnostic Trouble Codes

Air Bag and Safety Belt Pretensioner Supplemental Restraint System (SRS)

Self-Test/Continuous Memory and Clear DTCs

During vehicle operation, the RCM and OCSM 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 and OCSM 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. There is also an option to clear CMDTCs from the RCM and OCSM memory, as long as the concern no longer exists.

Once 127 ignition cycles have been recorded by the RCM since the concern was last detected, all RCM CMDTCs will automatically be removed from memory.

Once 127 ignition cycles have been recorded by the OCSM since the concern was last detected, all OCSM CMDTCs will automatically be removed from memory.


Lamp Fault Codes (LFCs)

This vehicle supports Lamp Fault Codes (LFCs) only when the RCM is in plant mode (flashing of the air bag warning indicator). A new RCM installed to a vehicle will be in plant mode until:

- Programmable Module Installation (PMI) has been carried out.
- the RCM sees a fault-free SRS (no DTCs present).

If a LFC is present after completing PMI, a fault is present in the SRS and on-demand DTCs must be retrieved and diagnosed.


Prove Out Procedure

Turn the ignition from OFF to the ON and monitor the air bag warning indicator with all SRS components connected. The IC module will illuminate the air bag warning indicator continuously for approximately 6 seconds and then turn off. If a SRS fault is present, the air bag warning indicator will:

- fail to light.
- remain lit continuously.
- flash.

The air bag warning indicator may not illuminate to indicate a fault is present until approximately 30 seconds after the ignition has been turned from the OFF to the ON position. This is the time required for the RCM to complete the testing of the SRS. If the air bag warning indicator is inoperative and a fault is detected, a chime will sound in a pattern of 5 sets of 5 beeps. If this occurs, the air bag warning indicator will need to be repaired before diagnosis can continue.