AIR BAG Indicator Circuit Malfunction

AIR BAG INDICATOR CIRCUIT MALFUNCTION

CIRCUIT DESCRIPTION
When the ignition is turned ON, the instrument panel cluster (IPC) flashes the AIR BAG indicator seven times. The inflatable restraint sensing and diagnostic module (SDM) performs tests to diagnose critical malfunctions within the SIR system. If no SIR system malfunctions exists, the SDM will request the IPC to turn the AIR BAG indicator OFF after it has flashed 7 times. The AIR BAG indicator is controlled by the SDM via class 2 serial data.

DIAGNOSTIC AIDS
- If ignition 1 voltage is outside of the normal operating voltage range (9-16 volts), the AIR BAG indicator will come ON solid with no DTCs set.
- The loss of serial data communication between the SDM and the instrument panel cluster (IPC) will cause the AIR BAG indicator to come ON solid. Refer to DTC U1001-U1254 in Computer/Integrating Systems. U1016

TEST DESCRIPTION

Steps 1-12:

The numbers below refer to the step numbers on the diagnostic table.
3. This step determines if ignition 1 voltage to the SDM is more than 9 volts.
4. This step determines if ignition 1 voltage to the SDM is more than 16 volts.
5. This step tests for an open or high resistance in the ignition 1 voltage circuit between the SDM and the SIR fuse.
6. This step tests for an open or high resistance in the ignition 1 voltage circuit that feeds the SIR fuse.
7. This step tests for an open or high resistance in the SDM ground circuit.