Seat Belt Indicator Circuit Malfunction
Seat Belt Indicator Circuit Malfunction
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 Instructions) provides an overview of each diagnostic category.
Circuit/System Description
The inflatable restraint sensing and diagnostic module (SDM) sends the status of the seat belt switch to the instrument panel cluster (IPC) via a class 2 serial data message. If either seat belt is unfastened, the SDM will send a message to the IPC to illuminate the fasten safety belt indicator for 72 seconds or until the seat belt is fastened.
Reference Information
Schematic Reference
Seat Belt Schematics ([1][2]Electrical Diagrams)
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 Relearning) for scan tool information.
Circuit/System Verification
Ignition ON, perform the IPC Display Test using the scan tool and verify the seat belt indicators illuminate.
If the indicators do not illuminate, replace the IPC.
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.
* IPC
* Seat belt switch
* SDM
* IPC harness connector
* Seat belt switch harness connector
* SDM harness connector
1. Ignition OFF, disconnect the harness connector at the applicable seat belt switch.
2. Ignition OFF, test for less than 5 ohm of resistance between the low reference circuit terminal B and ground.
• If greater than the specified range, test the low reference circuit terminal B for an open/high resistance. If the circuit tests normal, replace the SDM.
3. Ignition ON, verify the scan tool seat belt switch parameter is Unbuckled.
• If not the specified value, test the signal circuit terminal A 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 scan tool seat belt switch parameter is Buckled. For the passenger seat belt switch make sure someone is sitting in the passenger seat.
• If not the specified value, test the signal circuit terminal A for a short to voltage or open/high resistance. If the circuit tests normal, replace the SDM.
5. If all circuits test normal, test or replace the applicable seat belt switch.
Component Testing
1. Ignition OFF, disconnect the harness connector at the seat belt switch.
2. Test for infinite resistance between the signal circuit terminal A and the low reference terminal B.
• If not the specified value, replace the seat belt switch.
3. With the seat belt buckled, test for less than 5 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.
* Seat Belt Buckle Pretensioner Replacement (Removal and Replacement)
* Control Module References (Programming and Relearning) for SDM or IPC replacement, setup, and programming