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 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.

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.

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.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.