Diagnostic Instructions
Circuit/System 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 the ignition 1 voltage for the SDM is outside of the normal operating voltage range (9-16 volts), the air bag indicator will continuously illuminate and no DTC will set. |
| • | The loss of serial data communication between the SDM and the IPC will cause the air bag indicator to continuously illuminate. Refer to
DTC U1001-U1254
. |
Reference Information
Schematic Reference
SIR Schematics
Connector End View Reference
Component Connector End Views
Description and Operation
SIR System Description and Operation
Electrical Information Reference
Scan Tool Reference
Control Module References
for scan tool information
Circuit/System Testing
- Ignition ON, observe the function of the air bag indicator lamp, the indicator lamp will flash 7 times and go OFF.
| ⇒ | If the air bag indicator continuously illuminates, check the serial data signal circuit for a short to ground or an open/high resistance. |
| ⇒ | If the air bag indicator continually flashes, program the SDM. |
- Command the air bag lamp ON and OFF with a scan tool, the air bag indicator should turn ON and OFF while changing between the commanded states.
| ⇒ | If the air bag indicator does not illuminate, replace the IPC. |
- If all tests are normal, replace the SDM.
Repair Instructions
Perform the
Diagnostic Repair Verification
after completing the diagnostic procedure.
