Diagnostic Instructions
| • | Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. |
| • | Review Strategy Based Diagnosis for an overview of the diagnostic approach. |
| • | Diagnostic Procedure Instructions provides an overview of each diagnostic category. |
Diagnostic Fault Information
Circuit | Short to Ground | High Resistance | Open | Short to Voltage | Signal Performance |
|---|---|---|---|---|---|
Driver Seat Belt Sensor Signal | 1, B0072 02 | 2, B0072 05 | 2, B0072 05 | 2, B0072 01 | B0072 08 |
Driver Seat Belt Sensor Low Reference | -- | 2, B0072 05 | 2, B0072 05 | 2 | B0072 08 |
Passenger Seat Belt Sensor Signal | 1, B0073 02 | 2, B0073 05 | 2, B0073 05 | 2, B0073 01 | B0073 08 |
Passenger Seat Belt Sensor Low Reference | -- | 2, B0073 05 | 2, B0073 05 | 2 | B0073 08 |
1. Indicator will remain ON with seat belt buckled. 2. Indicator will illuminate only for the bulb test. | |||||
Circuit/System Description
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.
Reference Information
Schematic Reference
Connector End View Reference
Description and Operation
Seat Belt System Description and Operation
Electrical Information Reference
Scan Tool Reference
Control Module References for scan tool information
Circuit/System Verification
- Ignition ON, with a scan tool perform the IPC Display Test and verify the driver seat belt indicator is illuminated for 5 seconds.
- Monitor the scan tool Driver Seat Belt Switch parameter while connecting and disconnecting the seat belt. The parameter should display Buckled and Unbuckled when changing seat belt states.
| ⇒ | If the indicator does not illuminate, replace the IPC. |
Circuit/System Testing
- Ignition OFF, disconnect the harness connector at the seat belt switch.
- Ignition OFF, test for less than 1 ohm between the low reference circuit terminal 1 and ground.
- Ignition ON, verify the scan tool Driver Seat Belt Switch parameter displays Buckled.
- Install a 3A fused jumper wire between the signal circuit terminal 2 and the low reference circuit terminal 1. Verify the scan tool Driver Seat Belt Switch parameter displays Unbuckled.
- If all circuits test normal, test or replace the seat belt switch.
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
| ⇒ | 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. |
| ⇒ | If not the specified value, test the signal circuit for a short to ground. If the circuit tests normal replace the SDM. |
| ⇒ | 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. |
Component Testing
- Ignition OFF, disconnect the harness connector at the seat belt switch.
- With the seat belt buckled, test for infinite resistance between the signal circuit terminal 2 and the low reference terminal 1.
- With the seat belt unbuckled, test for less than 1 ohm between the signal circuit terminal 2 and the low reference terminal 1.
| ⇒ | If less than the specified value, replace the seat belt switch. |
| ⇒ | If greater than the specified range, replace the seat belt switch. |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
| • | Control Module References for SDM and IPC replacement, setup, and programming |
