Operation CHARM: Car repair manuals for everyone.

Malfunction Lamp / Indicator: Description and Operation

The AIR BAG warning lamp is located in the Instrument Panel Cluster (IPC). The inflatable restraint Sensing and Diagnostic Module (SDM) communicates with the IPC using the Class 2 serial data line. The SDM commands the IPC to turn the AIR BAG warning lamp ON and OFF through serial data communication. The SIR system uses the AIR BAG warning lamp to do the following:
^ Verify the lamp operation by flashing the lamp seven times when the ignition switch is ON.
^ Verify that the SDM is communicating with the IPC through serial data communication and that no SIR Diagnostic Trouble Codes (DTCs) are present by turning the lamp OFF after flashing seven times.
^ Warn the vehicles driver of SIR electrical system malfunctions which could potentially affect the operation of the SIR system.

These malfunctions could result in one or more of the following conditions:
- Non-deployment in the case of a frontal crash.
- Deployment for conditions less severe than intended.

The AIR BAG warning lamp is the key to driver notification of SIR system malfunctions.