Diagnostic Instructions
Circuit/System Description
When the ignition is turned ON, the instrument panel cluster (IPC) flashes the air bag 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 indicator steady, via serial data. If a preexisting malfunction exists, the air bag 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 turn the air bag indicator ON with no DTCs present, then disables all deployment loops.
Diagnostic Aids
A DTC B1370 may set if the ignition 1 circuit is outside the 9-16 volts range.
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
- Verify SDM DTCs are not set.
- Ignition OFF, monitor the IPC, ignition ON. The SIR warning indicator should flash then turn OFF.
⇒ | If the SIR warning indicator continually flashes, program the SDM. |
- Perform the Display Test in Instrument Panel Cluster/Special Functions. The Air Bag indicator should turn ON and OFF as commanded.
⇒ | If the air bag indicator does not illuminate as expected, replace the IPC. |
- If all circuits test normal, replace the SDM.
Repair Instructions
Perform the
Diagnostic Repair Verification after completing the diagnostic procedure.