Diagnostic Instructions

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

Diagnostic Instructions

The symptom chart can be used to help locate Supplemental Restraint System (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 Restraints Control Module (RCM) memory. Refer to Retrieve/Clear Continuous DTCs.

2. Run the On-Demand 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/Continuous Memory and Clear DTCs

During vehicle operation, the Restraints Control Module (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.

Once 128 key cycles have been recorded since the concern was last detected, the DTC will automatically be removed from memory.


Lamp Fault Code (LFC)

When the Restraints Control Module (RCM) detects a system fault, it will flash a coded sequence which is called a Lamp Fault Code (LFC) on the air bag warning indicator located in the Instrument Cluster (IC) module. The code is 2 digits. The first digit is flashed with a 0.5-second interval between pulses. There is a 2-second pause before the second digit is flashed, which also has a 0.5-second interval between pulses. There is a 5-second pause between each display of an LFC.

Each LFC is flashed 3 times after which the air bag indicator will remain lit for the remainder of the key-on cycle (except for DTC B2792 [cross link between firing loops] which only flashes one LFC). If there are multiple LFCs, each LFC will flash in order of priority.