Symptom Related Diagnostic Procedures

Schematic:

CIRCUIT DESCRIPTION
The ignition switch supplies Ignition voltage to the inflatable restraint Sensing and Diagnostic Module (SDM) at terminal A1 using the SIR Fuse. The ignition switch also supplies Ignition 1 voltage to the Instrument Panel Cluster (IPC). The AIR BAG warning lamp is controlled by the SDM via Class 2 serial data. When the ignition switch is first turned ON, the SDM responds by performing tests on the SIR system and then commanding the AIR BAG warning lamp OFF after it has flashed seven times.

DIAGNOSTIC AIDS

Test Step 1 - Step 5:

If battery voltage is outside of the normal operating voltage range (9 volts-16 volts), the AIR BAG warning lamp will come ON solid with no DTCs set.