| • | 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  | 
|---|---|---|---|---|
Front Fog Lamp Relay Control  | 1  | 2  | B2530 00  | --  | 
1. Fog Lamps Always On 2. Fog Lamps Inoperative  | ||||
Voltage is applied at all times to the fog lamp relay. When the fog lamp switch is placed in the ON position, a ground signal is applied to the body control module (BCM) through the fog lamp switch signal circuit. The BCM then applies a ground to the fog lamp relay control circuit. This engages the fog lamp relay and applies voltage through the FOG LAMP fuse to the front fog lamps.
| • | The ignition is ON. | 
| • | Park lamps must be ON and the fog lamps must be commanded ON. | 
The BCM detects a short to voltage on the front fog lamp control circuit.
The front fog lamps do not illuminate.
| • | The conditions for setting the DTC are no longer present. | 
| • | A history DTC clears after 100 malfunction-free ignition cycles. | 
Exterior Lighting Systems Description and Operation
Control Module References for scan tool information
Ignition ON, command the Fog Lamps ON with a scan tool. The Front Fog Lamp Relay Command parameter should display On and the front fog lamps should illuminate.
| ⇒ | If the test lamp illuminates, test the control circuit for a short to voltage. | 
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
| • | Control Module References for BCM replacement, setup, and programming |