2010 Cadillac Truck Escalade EXT AWD V8-6.2L Page 659

2010 Cadillac Truck Escalade EXT AWD V8-6.2L Page 659

DTC Descriptors

DTC B2540 02

- Rear Fog Lamp Control Circuit Short to Ground

DTC B2540 05

- Rear Fog Lamp Control Circuit Short to Battery or Open

Diagnostic Fault Information

Circuit/System Description

When the rear fog lamp switch is placed in the ON position, ground is applied to the auxiliary body control module (XBCM) through the rear fog

lamp switch circuit. The XBCM then applies voltage to the rear fog lamp control circuit to the rear fog lamp.

Conditions for Running the DTC

* Battery voltage must be between 9-16 V.

* Rear fog lamps ON.

Conditions for Setting the DTC

B2540 02

The BCM detects a short to ground in the rear fog lamp switch signal circuit.

B2540 05

The BCM detects a short to voltage or an open/high resistance in the rear fog lamp switch signal circuit.

Action Taken When the DTC Sets

The rear fog lamps will not operate when the park lamps are ON and the rear fog lamp switch is active.

Conditions for Clearing the DTC

* The condition responsible for setting the DTC no longer exists.

* A history DTC will clear once 100 consecutive malfunction-free ignition cycles have occurred.

Reference Information

Schematic Reference

Fog Lights Schematics (See: Diagrams/Electrical Diagrams/Lighting and Horns/System Diagram/Fog Lights Schematics)

Connector End View Reference

Component Connector End Views (See: Diagrams/Connector Views)

Description and Operation

Exterior Lighting Systems Description and Operation (See: Lighting and Horns/Description and Operation/Exterior Lighting Systems Description

and Operation)

Electrical Information Reference

* Circuit Testing (See: Testing and Inspection/Component Tests and General Diagnostics/General Electrical Diagnostic Procedures/Circuit

Testing/Circuit Testing)

* Connector Repairs (See: Testing and Inspection/Component Tests and General Diagnostics/General Electrical Diagnostic

Procedures/Connector Repairs/Connector Repairs)

* Testing for Intermittent Conditions and Poor Connections (See: Testing and Inspection/Component Tests and General Diagnostics/General

Electrical Diagnostic Procedures/Circuit Testing/Testing for Intermittent Conditions and Poor Connections)

* Wiring Repairs (See: Testing and Inspection/Component Tests and General Diagnostics/General Electrical Diagnostic Procedures/Wiring