• | 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 |
---|---|---|---|---|
Fog Lamp Relay B+ | -- | 1 | 1 | -- |
Fog Lamp Switch Signal | 2 | 2 | 2 | -- |
Fog Lamp Relay Control | 1 | 1 | B2530 00 | -- |
Fog Lamp Control | 1 | 1 | 1 | -- |
Fog Lamp - LF Ground | -- | 1 | -- | -- |
Fog Lamp - RF Ground | -- | 1 | -- | -- |
Fog Lamp Switch Ground | -- | 2 | -- | -- |
1. Front Fog Lamps Malfunction 2. Front Fog Lamp Switch Malfunction |
The fog lamp relay is supplied with battery voltage at all times. The fog lamp switch signal circuit is grounded momentarily by pressing the fog lamp switch. The body control module (BCM) energizes the fog lamp relay by applying ground to the fog lamp relay control circuit. When the fog lamp relay is energized, the relay switch contacts close and battery voltage is applied through the FOG LAMP fuse to the fog lamp supply voltage circuit which illuminates the fog lamps.
Exterior Lighting Systems Description and Operation
Control Module References for scan tool information
Ignition ON, observe the scan tool Front Fog Lamp Switch parameter while turning the front fog lamp switch ON and OFF. The parameter should change between Active and Inactive.
⇒ | If the parameter does not change between the commanded states, refer to Front Fog Lamp Switch Malfunction. |
⇒ | If the parameter changes between the commanded states, refer to Front Fog Lamps Malfunction. |
⇒ | 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 BCM. |
⇒ | 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 BCM. |
⇒ | If the test lamp illuminates, test the control circuit for a short to voltage. |
⇒ | If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance. |
⇒ | If the test lamp does not illuminate, test the B+ circuit for an open/high resistance. |
⇒ | If greater than the specified range, test the ground circuit for an open/high resistance. |
⇒ | If the fog lamps do not illuminate, test the control circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the inoperative fog lamp. |
⇒ | If the test lamp is always ON, test the control circuit for a short to ground. If the circuit tests normal, replace the BCM. |
⇒ | If the test lamp is always OFF, test the control circuit for a short to voltage or open/high resistance. If the circuit tests normal, replace the BCM. |
Ignition ON, with a scan tool perform the Display Test for the instrument panel cluster (IPC) and observe the fog lamp indicator.
⇒ | If the fog lamp indicator illuminates during the test, replace the BCM. |
⇒ | If the fog lamp indicator does not illuminate during the test or remains illuminated at all times, replace the IPC. |
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
• | Control Module References for BCM or IPC replacement, setup, and programming |