B2527

DTC B2527

Diagnostic Instructions

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

DTC Descriptor

DTC B2527
- Front Fog Lamps Circuit Low

Circuit/System Description

The body control module (BCM) monitors the front fog lamp switch signal circuit in order to determine when the fog lamp relay is to be energized. When the BCM senses that the front fog lamp switch signal circuit is grounded momentarily by pressing the fog lamp switch, the BCM energizes the fog lamp relay by grounding the fog lamp relay control circuit.

Conditions for Running the DTC

The battery voltage must be between 9-16 volts.

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.

Circuit/System Verification

Ignition ON, observe the scan tool front fog lamp switch parameter while pressing and releasing the front fog lamp switch. The reading should change between on and off.

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.

Component Testing

1. Ignition OFF, disconnect the harness connectors at the headlamp switch.
2. Test for infinite resistance between the front fog lamp switch signal terminal A X2 and the low reference terminal C X1 with the switch in the open position.

^ If not the specified value, replace the headlamp switch.

3. Test for less than 1 ohm of resistance between the front fog lamp switch signal terminal A X2 and the low reference terminal C X1 while pressing the front fog lamp switch.

^ If greater than the specified range, replace the headlamp switch.

Repair Instructions

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

* Headlamp Switch Replacement