Buick Regal: Airbag Indicator Malfunction (Passenger)

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.

Diagnostic Fault Information

1. Both indicators always OFF
2. The OFF indicator will not illuminate
3. The ON indicator will not illuminate
4. The OFF indictor always ON
5. The ON indicator always ON
* High resistance may cause the appropriate indicator to illuminate less bright than normal

Circuit/System Description

The passenger air bag ON/OFF indicators are used to notify the driver when the passenger presence system has enabled or disabled the passenger instrument panel air bag. When the ignition is turned ON, the ignition voltage is supplied to the passenger presence module. When the Inflatable Restraint Sensing and Diagnostic Module receives the appropriate serial data message from the passenger presence module the Inflatable Restraint Sensing and Diagnostic Module will then provide voltage to the appropriate indicator.

Reference Information

Schematic Reference

SIR Wiring Schematics

Connector End View Reference

Component Connector End View Index

Description and Operation

Supplemental Inflatable Restraint System Description and Operation

Electrical Information Reference

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

Scan Tool Reference

Refer to Control Module References for scan tool information.

Circuit/System Verification

1. Ignition ON.

2. Verify no other Inflatable Restraint Sensing and Diagnostic Module DTCs are set.

• If other Inflatable Restraint Sensing and Diagnostic Module DTCs are set

Diagnose those DTCs first. Refer to Diagnostic Trouble Code (DTC) List - Vehicle

• Go to next step: If no other Inflatable Restraint Sensing and Diagnostic Module DTCs are set

3. Verify the passenger air bag ON indicator and passenger air bag OFF indicators turn ON and OFF when commanded ON and OFF with a scan tool.

• If the passenger air bag indicators do not change

Refer to Circuit/System Testing

• Go to next step: If the passenger air bag indicators change

4. All OK.

Circuit/System Testing

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

• Passenger air bag disable on/off indicator.
• Passenger air bag disable on/off indicator wiring harness.

1. Ignition OFF, disconnect the harness connector at the S48C Multifunction Switch 1 - Instrument Panel.

2. Test for less than 10 Ω between the ground circuit terminal 1 and ground.

• If 10 Ω or greater

1. Test for less than 2 Ω in the ground circuit end to end.
   • If 2 Ω or greater, repair the open/high resistance in the circuit.
   • If less than 2 Ω, repair the open/high resistance in the ground connection.

• Go to next step: If less than 10 Ω

3. Ignition ON, command the Passenger Air Bag Off Indictor OFF with a scan tool.

4. Verify a test lamp does not illuminate between the control circuit terminal 2 and ground.

• If the test lamp illuminates

1. Ignition OFF, disconnect the X1 harness connector at the K36 Inflatable Restraint Sensing and Diagnostic Module. Ignition ON.
2. Test for less than 1 V between the control circuit and ground.
   • If 1 V or greater, repair the short to voltage on the circuit.
   • If less than 1 V, replace the K36 Inflatable Restraint Sensing and Diagnostic Module.

• Go to next step: If the test lamp does not illuminate

5. Command the Passenger Air Bag Off indicator ON with a scan tool.

6. Verify a test lamp illuminates between the control circuit terminal 2 and ground.

• If the test lamp does not illuminate

1. Ignition OFF, disconnect the X1 harness connector at the K36 Inflatable Restraint Sensing and Diagnostic Module.
2. Test for infinite resistance between the control circuit and ground.
   • If less than infinite resistance, repair the short to ground on the circuit.
3. Test for less than 2 Ω in each control circuit end to end.
   • If 2 Ω or greater, repair the open/high resistance in the circuit.
   • If less than 2 Ω, replace the K36 Inflatable Restraint Sensing and Diagnostic Module.

• Go to next step: If the test lamp illuminates

7. Command the Passenger Air Bag On Indicator OFF with a scan tool.

8. Verify a test lamp does not illuminate between the control circuit terminal 3 and ground.

• If the test lamp illuminates

1. Ignition OFF, disconnect the X1 harness connector at the K36 Inflatable Restraint Sensing and Diagnostic Module. Ignition ON.
2. Test for less than 1 V between the control circuit and ground.
   • If 1 V or greater, repair the short to voltage on the circuit.
   • If less than 1 V, replace the K36 Inflatable Restraint Sensing and Diagnostic Module.

• Go to next step: If the test lamp does not illuminate

9. Command the Passenger Air Bag On Indicator ON with a scan tool.

10. Verify a test lamp illuminates between the control circuit terminal 3 and ground.

• If the test lamp does not illuminate

1. Ignition OFF, disconnect the X1 harness connector at the K36 Inflatable Restraint Sensing and Diagnostic Module.
2. Test for infinite resistance between the control circuit and ground.
   • If less than infinite resistance, repair the short to ground on the circuit.
3. Test for less than 2 Ω in each control circuit end to end.
   • If 2 Ω or greater, repair the open/high resistance in the circuit.
   • If less than 2 Ω, replace the K36 Inflatable Restraint Sensing and Diagnostic Module.

• Go to next step: If the test lamp illuminates

11. Test or replace the S48C Multifunction Switch 1 - Instrument Panel.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the repair.

• Refer to Instrument Panel Assembly Replacement for S48C Multifunction Switch 1 - Instrument Panel replacement
• Refer to Control Module References for Inflatable Restraint Sensing and Diagnostic Module replacement, programming and setup

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