Diagnostic Instructions
Circuit/System Description
When the ignition is turned ON, the instrument panel cluster (IPC) flashes the SIR Air Bag warning indicator 7 times for a bulb check. The inflatable restraint sensing and diagnostic module (SDM) performs diagnostic tests on the SIR system during
the bulb check. If any malfunction exists the SDM will request the IPC to illuminate the air bag warning indicator steady, via serial data. If a preexisting malfunction exists, the air bag warning indicator will illuminate steady immediately after the ignition
is turned ON. If the ignition 1 voltage is outside of the normal operating voltage range 9-16 volts, the SDM will command the IPC to illuminate the air bag warning indicator with no DTCs present, then disables all deployment loops.
Diagnostic Aids
• | If the ignition 1 voltage for the SDM is outside of the normal operating voltage range, 9-16 volts, the air bag warning 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 warning indicator to continuously illuminate. |
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, with a scan tool, verify the Battery Voltage Signal Parameter is 9-16 volts.
- Ignition OFF, observe the SIR Air Bag warning indicator while turning the ignition ON. The SIR warning indicator should flash 7 times and then turn OFF.
⇒ | If the SIR warning indicator continually flashes, program the SDM. |
- Ignition ON, with a scan tool command the I/P indicators ON and OFF. The Air Bag indicator should turn ON and OFF when changing between the commanded states.
⇒ | If the air bag indicator does not illuminate as expected, replace the IPC. |
- If all tests are normal, replace the SDM.
Repair Instructions
Perform the
Diagnostic Repair Verification after completing the diagnostic procedure.