B2527

DTC B2527

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle (Initial Inspection and Diagnostic Overview) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Initial Inspection and Diagnostic Overview) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Initial Inspection and Diagnostic Overview) provides an overview of each diagnostic category.

DTC Descriptor
DTC B2527 00
- Front Fog Lamps Circuit Low

Diagnostic Fault Information





Circuit/System Description

The front fog lamp relay coil is supplied with battery voltage when the ignition is in the RUN or CRANK position. The front fog lamp relay switch is supplied with battery voltage at all times. The front fog lamp switch signal circuit is grounded momentarily by pressing the front fog lamp switch. The body control module (BCM) energizes the front fog lamp relay by applying ground to the front fog lamp relay control circuit. When the front fog lamp relay is energized, the relay switch contacts close and battery voltage is applied through the FRONT FOG fuse to the front fog lamp control circuit which illuminates the front fog lamps.

Conditions for Running the DTC

The battery voltage must be between 9-16 volts.

Fog Lamps must be commanded ON.

Conditions for Setting the DTC

The front fog lamp switch signal circuit is shorted to ground for 15 minutes.

Action Taken When the DTC Sets

The front fog lamps will be inoperative.

Conditions for Clearing the DTC

* This DTC will clear on current status after the condition for setting the fault is corrected.
* A history DTC will clear after 100 consecutive ignition cycles without a fault present.

Reference Information
Schematic Reference

Fog Lights Schematics (Fog Lights Schematics)
Connector End View Reference

Component Connector End Views (Connector Views)
Description and Operation

Exterior Lighting Systems Description and Operation (Exterior Lighting Systems Description and Operation)
Electrical Information Reference

* Circuit Testing (Component Tests and General Diagnostics)
* Connector Repairs (Component Tests and General Diagnostics)
* Testing for Intermittent Conditions and Poor Connections (Component Tests and General Diagnostics)
* Wiring Repairs (Component Tests and General Diagnostics)

Scan Tool Reference

Control Module References (Programming and Relearning) for scan tool information

Circuit/System Testing

1. Ignition OFF, disconnect the harness connector X2 at the headlamp switch.
2. Ignition ON, verify the scan tool front fog lamp switch parameter is OFF.

• If not the specified value test the front fog lamp switch signal circuit for a short to ground. If the circuit tests normal, replace the BCM.

3. If all circuits test normal, test or replace the headlamp switch.

Repair Instructions

Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.

* Headlamp Switch Replacement (Service and Repair)
* Control Module References (Programming and Relearning) for BCM replacement, programming, and setup.