The inflatable restraint sensing and diagnostic module (SDM) communicates the status of the driver seat belt switch to the instrument panel cluster (IPC). When the ignition switch is turned ON, with the driver seat occupied and the driver seat belt is unbuckled, the SDM sends a message to the IPC to illuminate the fasten safety belt indicator for 72 seconds or until the seat belt is fastened. If the seat belt is buckled before the ignition switch is turned ON, the fasten safety belt indicator will remain OFF. When the seat belt is unbuckled, the seat belt switch is Closed. When the seat belt is buckled, the seat belt switch is Open.

Schematic Reference

Seat Belt Schematics

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 command the I/P indicators ON and OFF. The driver seat belt indicator should turn ON and OFF when changing between the commanded states.

⇒	If the seat belt indicator is always OFF, replace the I/P cluster.

2. Ignition ON, with the driver seat occupied, buckle and unbuckle the driver seat belt. The driver seat belt indicator should go ON and OFF while buckling and unbuckling the driver seat belt.

1. Ignition OFF, disconnect the harness connector at the driver seat belt buckle.
2. Ignition OFF, test for less than 5 ohms between the seat belt switch low reference circuit terminal A and ground.

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

3. Ignition ON, test for 4.8-5.2 volts between the seat belt 5-volt signal circuit terminal B and ground.

⇒	If less than the specified range, test the signal circuit for a short to ground or open/high resistance. If the circuit tests normal, replace the SDM.

⇒	If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the SDM.

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

1. Ignition OFF, disconnect the harness connector at the driver seat belt buckle.
2. Test for infinite resistance between the signal terminal B and the low reference terminal A with the seat belt buckle buckled.

⇒	If not the specified value, replace the driver seat belt buckle.

3. Test for less than 2.0 ohms between the signal terminal B and the low reference terminal A with the seat belt buckle unbuckled.

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

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.