Seat Belt Indicator Circuit Malfunction - Driver
Diagnostic Instructions
Diagnostic Fault Information
Circuit
| Short to Ground
| High Resistance
| Open
| Short to Voltage
| Signal Performance
|
Driver Seat Belt Switch Signal
| 1
| 2
| 2
| 2
| -
|
Driver Seat Belt Switch Low Reference
| -
| 2
| 2
| 2
| -
|
1. Indicator will remain ON with seat belt buckled.
2. Indicator will illuminate only for the bulb check.
|
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. After receiving the message, the instrument panel cluster controls the illumination of the driver seat belt indicator.
Reference Information
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
Circuit/System Verification
- Command the instrument cluster all indicators ON and OFF with a scan tool. The driver seat belt indicator should turn ON and OFF as commanded.
⇒ | If the driver seat belt indicator does not turn ON and OFF as commanded
|
| Replace the P16 instrument cluster. |
⇓ | If the driver seat belt indicator does turn ON and OFF as commanded
|
- Monitor the scan tool Driver Seat Belt Switch parameter while buckling and unbuckling the seat belt. The parameter should display Buckled and Unbuckled when changing seat belt states.
⇒ | If the scan tool Driver Seat Belt Switch parameter does not display Buckled and Unbuckled when changing seat belt states
|
| Refer to Circuit/System Testing. |
⇓ | If the scan tool Driver Seat Belt Switch parameter does display Buckled and Unbuckled when changing seat belt states
|
- All OK.
Circuit/System Testing
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 harness connector |
• | SDM wiring harness connector |
- Vehicle OFF.
- Disconnect the harness connector at the B88 seat belt switch.
- Test for less than 5 Ω between the low reference circuit terminal 2 and ground.
3.1. | Disconnect the harness connector at the K36 SDM. |
3.2. | Test for less than 2 Ω in each control circuit end to end. |
⇒ | If 2 Ω or greater, repair the open/high resistance in the circuit. |
⇒ | If less than 2 Ω, replace the K36 SDM. |
- Vehicle in Service Mode.
- Verify the scan tool Driver Seat Belt Status parameter displays Buckled.
⇒ | If the scan tool Driver Seat Belt Status parameter does not display Buckled
|
5.1. | Disconnect the harness connector at the K36 SDM. |
5.2. | Test for infinite resistance between the seat belt switch signal circuit terminal 1 and ground. |
⇒ | If less than infinite resistance, repair the short to ground on the circuit. |
⇒ | If less than 2 Ω, replace the K36 SDM. |
⇓ | If the scan tool Driver Seat Belt Status parameter does display Buckled
|
- Install a 3 A fused jumper wire between the signal circuit terminal 1 and the low reference circuit terminal 2.
- Verify the scan tool Driver Seat Belt Status parameter displays Unbuckled.
⇒ | If the scan tool Driver Seat Belt Status parameter does not display Unbuckled
|
7.1. | Disconnect the harness connector at the K36 SDM. |
7.2. | Vehicle in Service Mode. |
7.3. | Test for less than 1 V between the signal circuit and ground. |
⇒ | If 1 V or greater, repair the short to voltage on the circuit. |
7.4. | Test for less than 2 Ω in each circuit end to end. |
⇒ | If 2 Ω or greater, repair the open/high resistance in the circuit. |
⇒ | If less than 2 Ω, replace the K36 SDM. |
⇓ | If the scan tool Driver Seat Belt Status parameter does display Unbuckled
|
- Replace the B88 seat belt switch.
Component Testing
- Vehicle OFF.
- Disconnect the harness connector at the B88 seat belt switch.
- B88 seat belt switch in the open position.
- Test for infinite resistance between the signal circuit terminal 1 and the ground terminal 2 at the B88 seat belt switch.
⇒ | If there is not infinite resistance
|
| Replace the B88 seat belt switch. |
⇓ | If there is infinite resistance
|
- B88 seat belt switch in the closed position.
- Test for less than 1 Ω between the signal circuit terminal 1 and the ground terminal 2 at the B88 seat belt switch.
| Replace the B88 seat belt switch. |
- All OK.
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
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