GM Service Manual Online
For 1990-2009 cars only

Diagnostic Instructions

    • Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
    • Review Strategy Based Diagnosis for an overview of the diagnostic approach.
    •  Diagnostic Procedure Instructions provides an overview of each diagnostic category.

Circuit/System Description

The passenger air bag ON/OFF indicators are used to notify the driver when the Passenger Presence System (PPS) has enabled or disabled the I/P inflator module. When the ignition is turned ON, the ignition voltage is supplied to the passenger air bag ON/OFF indicators and to the PPS module. The instrument panel cluster (IPC) grounds all indicator control circuits to the passenger air bag ON/OFF indicators for illumination. The IPC receives serial data messages from the supplemental inflatable restraints system to turn ON the indicators as necessary. The SDM uses messages sent from the PPS to help determine which indicator lamp(s) should be commanded on. When the ignition is turned ON, both PASSENGER AIR BAG ON/OFF indicators ON for 5 seconds for a bulb check.

Reference Information

Schematic Reference

SIR Schematics

Connector End View Reference

SIR Connector End Views

Description and Operation

SIR System Description and Operation

Electrical Information Reference

    •  Circuit Testing
    •  Connector Repairs
    •  Testing for Intermittent Conditions and Poor Connections
    •  Wiring Repairs

Scan Tool Reference

    •  Scan Tool Data List
    •  Scan Tool Data Definitions

Circuit/System Verification

    Important: The passenger air bag ON and OFF indicators may not operate as expected if there are supplemental inflatable restraint (SIR) DTCs. Repair all SIR DTC before proceeding with this diagnostic.

  1. Ignition ON, the passenger air bag ON and OFF indicators should both illuminate for approximately 5 seconds for a bulb check.
  2. Monitor the parameter Passenger Classification in Passenger Presence System with a scan tool. With the passenger seat unoccupied, the parameter should display Empty Seat. The passenger air bag OFF indicator should illuminate.
  3. Apply enough weight on the passenger seat to change the parameter display to Small. The passenger air bag OFF indicator should remain illuminated.
  4. Apply additional weight to change the parameter display to Large. The passenger air bag indicator should switch from OFF to ON within 5 seconds.

Circuit/System Testing

Important: When removing connectors inspect for damage, corrosion or poor connection. Damage or corrosion in the following requires repair or replacement of the affected component/connector.

   • Inflatable restraint passenger air bag on/off indicator.
   • Inflatable restraint passenger air bag on/off indicator wiring harness.

  1. Ignition OFF, disconnect the harness connector at the inflatable restraint passenger air bag ON/OFF indicator.
  2. Ignition ON, verify a test lamp illuminates between the ignition circuit terminal 4 and ground.
  3. If the test lamp does not illuminate, test the ignition circuit for a short to ground or an open/high resistance. If the circuit tests normal and the ignition circuit fuse is open, test or replace the inflatable restraint passenger air bag ON/OFF indicator.
  4. Connect a test lamp between the control circuit terminal 3 and the ignition circuit terminal 4.
  5. With the passenger seat unoccupied, then occupied the test lamp should switch states within 5 seconds.
  6. If the test lamp is always on, test the control circuit for a short to ground. If all circuits test normal replace the IPC.
    If the test lamp is always off, test the control circuit for a short to voltage or an open/high resistance. If all circuits test normal replace the IPC.
  7. Connect a test lamp between the control circuit terminal 1 and the ignition circuit terminal 4.
  8. With the passenger seat unoccupied, then occupied the test lamp should switch states within 5 seconds.
  9. If the test lamp is always on, test the control circuit for a short to ground. If all circuits test normal replace the IPC.
    If the test lamp is always off, test the control circuit for a short to voltage or an open/high resistance. If all circuits test normal replace the IPC.
  10. If all circuits test normal, replace the inflatable restraint passenger air bag ON/OFF indicator.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

    •  Inflatable Restraint Instrument Panel Module Indicator Replacement
    •  SIR/SRS Wiring Repairs
    •  Control Module References IPC replacement, setup, and programming