• | 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. |
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
---|---|---|---|---|
Rear Fog Lamp Switch Signal | 1 | 1 | -- | -- |
Rear Fog Lamp Control | B2540 02 | 1 | 2 | -- |
Rear Fog Lamp Ground | -- | 1 | -- | -- |
1. Rear fog lamp inoperative 2. Rear fog lamp always on |
The auxiliary body control module (XBCM) controls and supplies battery positive voltage to both the rear fog lamp and trailer rear fog lamp circuits.
Exterior Lighting Systems Description and Operation
Control Module References for Scan Tool Information
⇒ | If not the specified value, refer to the rear fog lamp switch circuit test. |
⇒ | If the front fog lamp is always on or always off, refer to the fog lamp control circuit test. |
⇒ | If greater than the specified range, test the ground circuit for an open/high resistance. |
⇒ | If not the specified value, test the signal circuit terminal 6 for a short to ground. If the circuit tests normal, replace the XBCM. |
⇒ | 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 XBCM. |
⇒ | If greater than the specified range, test the ground circuit for an open/high resistance. |
⇒ | If the test lamp is always ON, test the control circuit for a short to voltage. If the circuit tests normal, replace the XBCM. |
⇒ | If the test lamp is always OFF, test the control circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the XBCM. |
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
• | Control Module References for XBCM replacement, programming, and setup |