GM Service Manual Online
For 1990-2009 cars only

Circuit 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 ignition 1 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.

Diagnostic Aids

The following can cause an intermittent condition:

    • A short in the passenger air bag OFF indicator control circuit
    • A short in the passenger air bag ON indicator control circuit
    • An open or high resistance in the passenger air bag OFF indicator control circuit
    • An open or high resistance in the passenger air bag ON indicator control circuit

Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems.

Test Description

The numbers below refer to the step numbers on the diagnostic table.

  1. This step tests the ignition 1 voltage circuit between the inside rearview mirror and the underhood fuse block for a short to ground, a high resistance, or an open.

  2. This step tests the passenger air bag OFF indicator control circuit for a short to ground, a high resistance, or an open.

  3. This step test the passenger air bag ON indicator control circuit for a short to ground, a high resistance, or an open.

  4. This step tests the PPS module for proper operation.

Step

Action

Yes

No

Schematic Reference: SIR Schematics

Connector End View Reference: SIR Connector End Views or Stationary Windows Connector End Views in Stationary Windows

1

Did you perform the Diagnostic System Check - Vehicle?

Go to Step 2

Go to Diagnostic System Check - Vehicle in Vehicle DTC Information

2

  1. Turn OFF the ignition.
  2. Disconnect the passenger presence system (PPS) module connector.
  3. Inspect the PPS module connector for corrosion or damage. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 10

Go to Step 3

3

  1. Disconnect the inside rearview mirror connector located at the back of the mirror.
  2. Inspect the inside rearview mirror connector for corrosion or damage. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 10

Go to Step 4

4

  1. Turn OFF the ignition.
  2. Test the ignition 1 voltage circuit between the inside rearview mirror and the underhood fuse block for a short to ground, a high resistance, or an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step  10

Go to Step 5

5

Test the passenger air bag OFF indicator control circuit for a short to ground, a high resistance, or an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 10

Go to Step 6

6

Test the passenger air bag ON indicator control circuit for a short to ground, a high resistance, or an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 10

Go to Step 7

7

  1. Turn OFF the ignition.
  2. Connect a test lamp between the ignition 1 voltage circuit and the passenger air bag OFF indicator control circuit at the inside rearview mirror connector terminals.
  3. Empty the front passenger seat.
  4. Turn On the ignition, with the engine OFF.

Does the test lamp illuminate?

Go to Step 8

Go to Step 9

8

Important: When replacing the inside rearview mirror, perform the Compass Calibration and Magnetic Variance when the repair is complete.

Replace the rearview mirror. Refer to Inside Rearview Mirror Replacement in Stationary Windows.

Did you complete the replacement?

Go to Step 10

--

9

Replace the PPS. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming.

Did you complete the replacement?

Go to Step 10

--

10

  1. Reconnect all PPS and rearview mirror system components.
  2. Verify that all components, connectors, and connector position assurances (CPAs) are properly mounted.
  3. Use the scan tool in order to clear the SIR and PPS DTCs.
  4. Rezero the PPS. Refer to Passenger Presence System Programming and Setup in Programming and Setup.
  5. Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 2