GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 GMC_Truck 🢒 2005 🢒 GMC C Sierra - 2WD 🢒 Vehicle Control Systems 🢒 Vehicle DTC Information 🢒 Passenger Presence System Indicator Circuit Malfunction

Diagnostic Fault Information

Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.

Circuit/System Description

The PASSENGER AIR BAG ON/OFF indicators located on the rearview mirror are used to notify the driver when the passenger presence system (PPS) has enabled or disabled the instrument panel (I/P) inflator module. The PPS air bag indicators will also inform the driver of any PPS malfunctions. When the ignition is turned on, the PPS module is supplied with voltage and 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 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 PPS malfunction.

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 Testing
  1. Ignition OFF, disconnect the harness connector at the inside rearview mirror.
  2. Ignition ON, verify a test lamp illuminates between the ignition voltage circuit terminal 13 and ground.
    3. ⇒If the test lamp does not illuminate, test the ignition circuit for a short to ground or an open/high resistance.
  3. Reconnect the harness connector at the inside rearview mirror.
  4. Ignition OFF, disconnect the harness connector at the PPS module.
  5. Ignition OFF, test for less than 1.0 ohm of resistance between the ground circuit terminal 5 and ground.
    6. ⇒If greater than the specified range, test the ground circuit for an open/high resistance.
  6. Ignition ON, verify a test lamp illuminates between the ignition voltage circuit terminal 9 and ground.
    7. ⇒If the test lamp does not illuminate, test the ignition circuit for a short to ground or an open/high resistance.
  7. Test for B+ between the control circuit terminal 1 and ground.
    8. ⇒If less than the specified range, test the control circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the inside rearview mirror.
  8. Test for B+ between the control circuit terminal 2 and ground.
    9. ⇒If less than the specified range, test the control circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the inside rearview mirror.
  9. If all circuits test normal, test or replace the PPS module.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

    •  Inside Rearview Mirror Replacement
    •  Control Module References for PPS module replacement, setup, and programming.