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 | Open/High Resistance | Short to Voltage | Signal Performance |
|---|---|---|---|---|
Low Reference | -- | 2 | -- | -- |
Seat Belt Switch Signal | 1 | 2 | -- | -- |
Ignition 1 Voltage | 3 | 3 | -- | -- |
Passenger Seat Belt Indicator Control | 4 | 5 | -- | -- |
| ||||
Circuit/System Description
The seat belt buckle switch is located within the seat belt buckle assembly and provides an input to the inflatable restraint sensing and diagnostic module (SDM). The SDM supplies a low reference circuit and a seat belt switch signal circuit to determine a buckled or unbuckled condition.
If the SDM determines the driver seat belt has not been buckled, the SDM will send a serial data message to the instrument panel cluster (IPC) to illuminate the seat belt warning indicator. If the SDM determines that a passenger is sitting in the passenger seat and the seat belt has not been buckled, the SDM will send a serial data message to the passenger presence system (PPS) display to illuminate the passenger seat belt warning indicator.
Reference Information
Schematic Reference
Connector End View Reference
Description and Operation
SIR System Description and Operation
Electrical Information Reference
Scan Tool Reference
Control Module References for scan tool information
Circuit/System Verification
- Ignition ON, observe the scan tool Passenger Seat Belt Switch parameter while buckling and unbuckling the passenger seat belt. The parameter should change between Buckled and Unbuckled.
- Ignition ON, while sitting in the passenger seat with the seat belt unbuckled, verify the passenger seat belt warning indicator is illuminated on the PPS display.
| ⇒ | If the parameter does not cycle between the specified values, refer to Passenger Seat Belt Switch Circuit Malfunction. |
| ⇒ | If the indicator is not illuminated, replace the PPS display. |
Circuit/System Testing
Important: When removing connectors, inspect for damage or corrosion. Damage or corrosion in the following requires repair or replacement of the appropriate component/connector:
• The SDM • The SDM wiring harness connector • The seat belt buckle • The seat belt buckle wiring harness connector
Passenger Seat Belt Switch Circuit Malfunction
- Ignition OFF, disconnect the harness connector at the passenger seat belt switch.
- Ignition OFF, test for less than 10 ohms between the low reference circuit terminal B X1 and ground.
- Ignition ON, verify the scan tool Passenger Seat Belt Switch parameter is Unbuckled.
- Install a 3A fused jumper wire between the signal circuit terminal A X1 and the low reference circuit terminal B X1. Verify the scan tool Passenger Seat Belt Switch parameter is Buckled.
- If all circuits test normal, test or replace the seat belt buckle assembly.
| ⇒ | If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the SDM. |
| ⇒ | If not the specified value, test the signal circuit terminal A X1 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. |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
| • | Control Module References for SDM replacement, setup, and programming |
