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 instrument panel (I/P) inflator module. When the ignition is turned ON, the PPS module will commands both PASSENGER AIR BAG ON/OFF indicators ON for 5 seconds. The PPS module conducts tests on the PPS components and circuits while both PASSENGER AIR BAG ON/OFF indicators are ON. If no malfunctions are detected, the PPS module will turn the PASSENGER AIR BAG indicator ON or OFF, depending on the status of the PPS. If a malfunction is detected, the PPS module will store a DTC, default the PPS to the OFF state, and communicate with the sensing and diagnostic module (SDM) that a DTC has been set. The SDM will request the instrument panel cluster (IPC) to turn the AIR BAG indicator ON to notify the driver of a malfunction.

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

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

Scan Tool Reference

Control Module References for scan tool information

Circuit/System Testing

Important: When removing connectors inspect for damage or corrosion. Damage or corrosion in the following requires repair or replacement of the affected.

   • PPS module
   • PPS module wiring harness
   • The IPC module
   • The IPC module wiring harness
   • SDM
   • SDM wiring harness

  1. Ignition OFF, disconnect the harness connector at the inflatable restraint passenger air bag On/Off indicator.
  2. Ignition OFF, test for less then 1 ohm between the ground circuit terminal 2 and ground.
  3. If greater then the specified range, test the ground circuit for an open/high resistance.
  4. Ignition ON, verify a test lamp illuminates between the ignition circuit terminal 4 and ground.
  5. 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.
  6. Connect a test lamp between the control circuit terminal 3 and the ignition circuit terminal 4. With the passenger seat unoccupied, then occupied the test lamp should switch states within 5 seconds.
  7. 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.
  8. Connect a test lamp between the control circuit terminal 1 and the ignition circuit terminal 4. 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
    •  Control Module References for IPC and SDM replacement, setup, and programming