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 |
|---|---|---|---|---|
Fog Lamp Relay Control | B2530 02 | B2530 05 | B2530 05 | -- |
Fog Lamp Voltage Supply | 2 | 2 | 1 | -- |
Front Fog Lamp Switch Signal | 1 | 2 | -- | -- |
Fog Lamp Relay Ground | -- | 2 | 2 | -- |
Fog Lamp - LF Ground | -- | 2 | 2 | -- |
Fog Lamp - RF Ground | -- | 2 | 2 | -- |
Fog Lamp Switch Ground | -- | 2 | 2 | -- |
1. Fog Lamps Always On 2. Fog Lamps Inoperative | ||||
Circuit/System Description
When the fog lamp switch is placed in the ON position, ground is applied through the fog lamp switch signal circuit at G201 to the body control module (BCM). The BCM applies battery voltage through the fog lamp relay control circuit to the coil side of the fog lamp relay and the fog lamps ON indicator located on the fog lamp switch. Battery voltage is applied at all times from the FOG LP fuse to the switch side of the fog lamp relay. When the relay coil is energized, the relay switch contacts close and allow battery voltage to be applied from the FOG LP fuse, through the relay switch contacts, to the fog lamps. Ground for the fog lamps is applied at all times at G101 for the left fog lamp and G102 for the right fog lamp. G101 also serves as ground for the coil side of the fog lamp relay.
Reference Information
Schematic Reference
Connector End View Reference
Lighting Systems Connector End Views
Electrical Information Reference
Scan Tool Reference
Circuit/System Testing
- Ignition OFF, disconnect the fog lamp switch.
- Connect a test lamp between the fog lamp relay control circuit that supplies the fog lamp switch indicator and ground.
- Ignition ON, with a scan tool, command the front fog lamp relay command ON. The test lamp should illuminate when the fog lamps are commanded ON.
- Verify that a test lamp illuminates between the fog lamp relay control circuit that supplies the fog lamp switch indicator and the fog lamp switch ground circuit.
- If all circuits test normal, test or replace the fog lamp switch.
| ⇒ | If the test lamp does not illuminate, repair the fog lamp relay control circuit that supplies the fog lamp switch indicator for a short to ground or an open/high resistance. |
| ⇒ | If the test lamp does not illuminate, repair the fog lamp switch ground circuit for an open/high resistance. |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
