GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Cadillac 🢒 2005 🢒 CTS 🢒 Restraints 🢒 SIR 🢒 Passenger Presence System Indicator Circuit Malfunction

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. 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; then 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 are possible causes of the malfunction:

    • 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

Thoroughly inspect the wiring and the connectors. An incomplete inspection of the wiring and the connectors may result in a misdiagnosis, causing a part replacement with the reappearance of the malfunction. If an intermittent malfunction exists, refer to Testing for Intermittent Conditions and Poor Connections .

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, high resistance, or an open.

    2.

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

    3.

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

    4.

  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

1

Did you perform the Diagnostic System Check - Vehicle?

Go to Step 2

Go to Diagnostic System Check - Vehicle

2
  1. Turn OFF the ignition.
  2. Disconnect the passenger presence system (PPS) module connector located under the front passenger seat. Refer to Inflatable Restraint Passenger Presence System Replacement - Front .
  3. Inspect the PPS module connector for damage or corrosion that may cause the malfunction. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .

Does connector exhibits any signs of damage or corrosion?

Go to Step 10

Go to Step 3

3
  1. Disconnect the inside rearview connector located on the back side of the mirror.
  2. Inspect the rearview mirror connector for damage or corrosion that may cause the malfunction. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .

Does connector exhibits any signs of damage or corrosion?

Go to Step 10

Go to Step 4

4

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

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 between the rearview mirror and the PPS for a short to voltage, high resistance, or an open. Refer to Circuit Testing and Wiring Repairs .

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 between the rearview mirror and the PPS for a short to voltage, high resistance, or an open. Refer to Circuit Testing and Wiring Repairs .

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 terminal.
  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
  1. Turn OFF the ignition.

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

  2. Replace the rearview mirror. Refer to Control Module References for replacement, setup, and programming.

Did you complete the replacement?

Go to Step 10

--

9
  1. Turn OFF the ignition.

    2. Important: The PPS is a calibrated system. The PPS must be check for preloads after replacement.

  2. Replace the PPS, the PPS is only serviceable as PPS and seat bottom foam assembly. Refer to Control Module References for replacement, setup, and programming.

Did you complete the replacement?

Go to Step 10

--

10
  1. Connect all SIR and PPS components.
  2. Turn ON the ignition, with the engine OFF.
  3. Use the scan tool in order to clear the DTCs.
  4. Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text.

Does the DTC reset?

Go to Step 2

System OK