Circuit Description
When the ignition switch is first turned ON, Ignition 1 voltage is applied from the GAUGES fuse to Redundant Indicator Ignition 1, terminal B2, and to the AIR BAG warning lamp which is connected to SIR Indicator, terminal B1. The AIR BAG fuse applies system voltage to the Ignition 1 inputs, terminals A9 and A10. The inflatable restraint Diagnostic Energy Reserve Module (DERM) Responds by flashing the AIR BAG warning lamp seven times. If Ignition 1 is outside of the normal operating voltage range, the AIR BAG warning lamp come on solid with no DTC set.
When the engine is being cranked, Ignition 1 voltage is applied from the CRANK fuse to the DERM at the Crank input. The DERM responds by grounding the SIR Indicator output until Ignition 1 voltage is removed from the Crank input. This results in the AIR BAG warning lamp being on during cranking.
After cranking, the DERM will flash the AIR BAG warning lamp six times.