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 Instructions) provides 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. After receiving the message, the instrument panel cluster controls the illumination of the driver seat belt indicator.

Reference Information
Schematic Reference

Seat Belt Schematics (Electrical Diagrams)
Connector End View Reference

Component Connector End Views (Connector Views)
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

1. Ignition ON, with a scan tool command the instrument cluster to turn on all indicators and verify the driver seat belt indicator is illuminated for 5 seconds.

• If the indicator does not illuminate, replace the P16 instrument panel cluster.

2. With the scan tool, monitor the Driver Seat Belt Status parameter while buckling and unbuckling the seat belt. The parameter should display Buckled and Unbuckled when buckling and unbuckling the seat belt.

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 component/connector:

* B88 Seat belt switch
* Seat belt switch harness connector
* K36 SDM
* SDM wiring harness connector

1. Ignition OFF, disconnect the harness connector at the B88 seat belt switch.
2. Test for less than 5 ohm between the ground circuit terminal B and ground.

• If greater than the specified range, test the ground circuit for an open/high resistance. If the circuit tests normal replace the K36 SDM.

3. Ignition ON, verify the scan tool Driver Seat Belt Status parameter displays Buckled.

• If not the specified value, test the signal circuit terminal A for a short to ground. If the circuit tests normal replace the K36 SDM.

4. Install a 3 A fused jumper wire between the circuit terminal A and the ground circuit terminal B. Verify the scan tool Driver Seat Belt Status parameter displays Unbuckled.

• If not the specified value, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the K36 SDM.

5. If all circuits test normal, test or replace the B88 seat belt switch.

Component Testing

1. Ignition OFF, disconnect the harness connector at the B88 seat belt switch.
2. Test for infinite resistance between the signal circuit terminal A and the ground terminal B, at the switch, with the switch in the open position.

• If not the specified value, replace the B88 seat belt switch.

3. Test for less than 5 ohm between the signal circuit terminal A and the ground terminal B, at the switch, with the switch in the closed position.

• If greater than the specified range, replace the B88 seat belt switch.

Repair Instructions

Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.

* Driver or Passenger Seat Belt Buckle Replacement (Driver or Passenger Seat Belt Buckle Replacement)
* Control Module References (Programming and Relearning) for SDM and instrument panel cluster replacement, setup, and programming