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.

Schematic Reference

Connector End View Reference

Electrical Information Reference

Scan Tool Reference

1. Ignition ON, perform the IPC Display Test using the scan tool and verify the driver seat belt indicator is illuminated.

⇒	If the indicator does not illuminate, replace the IPC.

2. Monitor the Driver Seat Belt Switch parameter while connecting and disconnecting the seat belt. The parameter should display Buckled and Unbuckled as appropriate.

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 IPC

•	Left seat belt switch

•	Left seat belt switch harness connector

•

SDM

•	SDM harness connector

1. Ignition OFF, disconnect the harness connector at the seat belt switch - left.
2. Ignition ON, using a scan tool, verify the Driver Seat Belt Switch parameter in Supplemental Inflatable Restraints is Buckled.

⇒	If the parameter is Unbuckled, test the signal circuit for a short to ground. If the circuit tests normal replace the SDM.

3. Install a 3-amp fused jumper wire between the signal circuit terminal A and the low reference circuit terminal B. Verify the scan tool Driver Seat Belt Switch parameter is Unbuckled.

⇒	If the parameter is Buckled, test the signal and the low reference circuits for high resistance/open or a short to voltage. If the circuits test normal, replace the SDM.

4. If all circuits test normal, test or replace the applicable seat belt switch - left.

1. 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 value, replace the left seat belt switch.

2. 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 left seat belt switch.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.