The passenger 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 passenger 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 P16 instrument panel cluster.

2. Monitor the scan tool Passenger Seat Belt Status parameter while connecting and disconnecting the seat belt. The parameter should display Buckled and Unbuckled when changing seat belt states.

Note: 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 harness connector

1. Ignition OFF, disconnect the harness connector at the B88P passenger seat belt switch.
2. Ignition OFF, test for less than 1 Ω between the low reference circuit terminal 2 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 K36 SDM.

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

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

4. Install a 3A fused jumper wire between the signal circuit terminal 1 and the low reference circuit terminal 2. Verify the scan tool Passenger 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 B88P passenger seat belt switch.

1. Ignition OFF, disconnect the harness connector at the B88P passenger seat belt switch.
2. With the seat belt buckled, test for infinite resistance between the signal circuit terminal 1 and the low reference terminal 2.

⇒	If less than the specified value, replace the B88P passenger seat belt switch.

3. With the seat belt unbuckled, test for less than 1 Ω between the signal circuit terminal 1 and the low reference terminal 2.

⇒	If greater than the specified range, replace the B88P passenger seat belt switch.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.