Seat Belt Indicator Circuit Malfunction - Driver
Seat Belt Indicator Circuit Malfunction - Driver
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis Strategy Based Diagnosis for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions Diagnostic Procedure Instructionsprovides an overview of each diagnostic category.
Diagnostic Fault Information
Circuit/System Description
The driver seat belt switch is a 2-wire switch wired to the inflatable restraint sensing and diagnostic module (SDM) using a signal circuit and a low reference circuit. When the seat belt is unbuckled the switch is closed, and when the seat belt is buckled the switch is open. The SDM sends the status of the driver seat belt via serial data to the instrument panel cluster (IPC). After receiving the message, the IPC controls the illumination of the driver seat belt indicator.
Reference Information
Schematic Reference
* Seat Belt Schematics [1][2]Electrical Diagrams
* SIR Schematics [1][2]Air Bag Systems
Connector End View Reference
Component Connector End Views Connector End Views By Name
Description and Operation
Seat Belt System Description and Operation Description and Operation
Electrical Information Reference
* Circuit Testing Circuit Testing
* Connector Repairs Connector Repairs
* Testing for Intermittent Conditions and Poor Connections Testing for Intermittent Conditions and Poor Connections
* Wiring Repairs Wiring Repairs
Scan Tool Reference
Control Module References Programming and Relearningfor Scan Tool Information
Circuit/System Verification
1. Ignition ON, with a scan tool perform the IPC Display Test and verify the driver seat belt indicator is illuminated for 5 seconds.
• If the indicator does not illuminate, replace the IPC.
2. Monitor the SDM Driver Seat Belt Switch parameter while connecting and disconnecting the seat belt. The parameter should display Buckled and Unbuckled when changing seat belt states.
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 component/connector.
* The seat belt switch
* The seat belt switch harness connector
* The SDM
* The SDM harness connector
1. Ignition OFF, disconnect the harness connector at the seat belt switch.
2. Test the resistance between the low reference circuit terminal B and signal circuit terminal A of the switch (buckle side) while connecting and disconnecting the seat belt. The resistance should switch between infinity and less than 2 ohms.
3. Ignition ON, using a scan tool, verify the SDM Driver Seat Belt Switch parameter display is Buckled.
• If the parameter is Unbuckled, test the seat belt switch signal circuit for a short to ground. If the circuit tests normal replace the SDM.
4. Install a 3-amp fused jumper wire between the signal circuit terminal A and the low reference circuit terminal B. Verify the SDM Driver Seat Belt Switch parameter display is Unbuckled.
• If the parameter is Buckled, test the signal and the low reference circuits for open/high resistance or a short to voltage. If the circuits test normal, replace the SDM.
5. If all circuits test normal, test or replace the seat belt switch.
Component Testing
1. Ignition OFF, disconnect the harness connector at the seat belt switch.
2. With the seat belt buckled, test for infinite resistance between the signal circuit terminal A and the low reference terminal B.
• If not the specified range, replace the seat belt switch.
3. With the seat belt unbuckled, test for less than 2 ohms of resistance between the signal circuit terminal A and the low reference terminal B.
• If greater than the specified range, replace the seat belt switch.
Repair Instructions
Perform the Diagnostic Repair Verification Verification Tests after completing the diagnostic procedure.
* Front Seat Belt Buckle Replacement
* Control Module References Programming and Relearningfor SDM or IPC replacement, setup, and programming