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

Component Connector End Views

Description and Operation

Seat Belt System Description and Operation

Electrical Information Reference

Scan Tool Reference

Control Module References for scan tool information

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 scan tool Driver Seat Belt Switch parameter while connecting and disconnecting the seat belt. The parameter should display Buckled and Not Buckled when changing seat belt states.

Important: When removing connectors inspect for damage or corrosion. Damage or corrosion in the following requires repair or replacement of the affected component/connector.

•	Seat belt switch

•	Seat belt switch harness connector

•

SDM

•	SDM wiring harness connector

1. Ignition OFF, disconnect the harness connector at the seat belt switch.
2. Ignition OFF, test for less than 1 ohm between the low reference circuit terminal A and ground.

⇒	If greater than the specified range, test the low reference circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the SDM.

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

⇒	If not the specified value, test the signal circuit for a short to ground. If the circuit tests normal replace the SDM.

4. Install a 3A fused jumper wire between the signal circuit terminal B and the low reference circuit terminal A. Verify the scan tool Driver Seat Belt Switch parameter displays Not Buckled.

⇒	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 SDM.

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

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 B and the low reference terminal A.

⇒	If less than the specified value, replace the seat belt switch.

3. With the seat belt unbuckled, test for less than 1 ohm between the signal circuit terminal B and the low reference terminal A.

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

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.