2010 Cadillac Truck SRX AWD V6-2.8L Turbo Page 569
The BCM detects a short to ground on the front fog lamp relay control circuit.
Action Taken When the DTC Sets
The front fog lamps will always be illuminated.
Conditions for Clearing the DTC
* The DTC will be current for as long as the fault is present.
* When the fault is no longer present, the DTC will be a history DTC.
* A history DTC will clear after 50 ignition cycles.
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/Connector End Views By Name)
Description and Operation
Exterior Lighting Systems Description and Operation (See: Lighting and Horns/Description and Operation/Exterior Lighting Systems)
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
Repairs/Wiring Repairs)
Scan Tool Reference
Control Module References (See: Testing and Inspection/Programming and Relearning)
Circuit/System Verification
Ignition ON, command the Fog Lamps ON and OFF with a scan tool. The front fog lamps should turn ON and OFF when changing between the
commanded states.
Circuit/System Testing
1. Ignition OFF, disconnect the X5 harness connector at the K9 BCM.
2. Ignition ON, test for greater than 10V between the control circuit terminal 10 and ground.
瀚慖f less than the specified range, test the control circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace
the X50A underhood fuse block.
3. If all circuits test normal, replace the K9 BCM.
Repair Instructions
Perform the Diagnostic Repair Verification (See: Verification Tests) after completing the diagnostic procedure.
* Fuse Block Replacement (See: Maintenance/Fuses and Circuit Breakers/Fuse Block/Service and Repair/Removal and Replacement/Fuse
Block Replacement)
* Control Module References (See: Testing and Inspection/Programming and Relearning) for BCM replacement, programming and setup
B2540
DTC B2540
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Diagnostic System
Check - Vehicle) prior to using this diagnostic procedure.
