2010 Cadillac CTS Sedan AWD V6-3.6L Page 501
and Operation)
Electrical Information Reference
* Circuit Testing (See: Testing and Inspection/Component Tests and General Diagnostics/Circuit Testing/Circuit Testing)
* Connector Repairs (See: Testing and Inspection/Component Tests and General Diagnostics/Connector Repairs/Connector Repairs)
* Testing for Intermittent Conditions and Poor Connections (See: Testing and Inspection/Component Tests and General Diagnostics/Circuit
Testing/Testing for Intermittent Conditions and Poor Connections)
* Wiring Repairs (See: Testing and Inspection/Component Tests and General Diagnostics/Wiring Repairs/Wiring Repairs)
Scan Tool Reference
Control Module References (See: Testing and Inspection/Programming and Relearning) for scan tool information
Circuit/System Testing
1. Ignition OFF, disconnect the front fog lamp relay.
2. Connect a test lamp between the B+ circuit terminal 85 and the control circuit terminal 86.
3. Command the Fog Lamps ON and OFF with a scan tool. The test lamp should turn ON and OFF when changing between the commanded
states.
瀚慖f the test lamp is always ON, test the control circuit for a short to ground. If the circuit tests normal, replace the BCM.
瀚慖f the test lamp is always OFF, test the control circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace
the BCM.
4. If all circuits test normal, replace the front fog lamp relay.
Repair Instructions
Perform the Diagnostic Repair Verification (See: Verification Tests) after completing the diagnostic procedure.
* Relay Replacement (Attached to Wire Harness) (See: Power and Ground Distribution/Power Distribution Relay/Service and Repair/Relay
Replacement (Attached to Wire Harness))Relay Replacement (Within an Electrical Center) (See: Power and Ground Distribution/Power
Distribution Relay/Service and Repair/Relay Replacement (Within an Electrical Center))
* Underhood Electrical Center or Junction Block Replacement (See: Maintenance/Fuses and Circuit Breakers/Fuse Block/Service and
Repair/Removal and Replacement/Underhood Electrical Center or Junction Block Replacement)
* Control Module References (See: Testing and Inspection/Programming and Relearning) for BCM replacement, setup, and programming
B2545
DTC B2545
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.
* Review Strategy Based Diagnosis (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Strategy Based Diagnosis) for an
overview of the diagnostic approach.
* Diagnostic Procedure Instructions (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Diagnostic Procedure
Instructions) provides an overview of each diagnostic category.
DTC Descriptor
DTC B2545 00
- Backup Lamps Circuit
Diagnostic Fault Information
Circuit/System Description
When the transmission is placed in the REVERSE position, the transmission control module (TCM) sends a serial data message to the body control
module (BCM). The message indicates that the gear selector is in the REVERSE position. The BCM applies battery voltage to the backup lamps
