2010 Cadillac Truck SRX FWD V6-3.0L Page 571

2010 Cadillac Truck SRX FWD V6-3.0L Page 571

Ignition ON, command the Rear Fog Lamp(s) Relay ON and OFF with a scan tool. The rear fog lamp should turn ON and OFF when changing

between the commanded states.

Circuit/System Testing

1. Ignition OFF, disconnect the harness connector at the E5 fog lamp-rear.

2. Test for less than 30 ohm between the ground circuit terminal C and ground.

瀚慖f greater than the specified range, test the ground circuit for an open/high resistance.

3. Connect a test lamp between the control circuit terminal A and ground.

4. Ignition ON, command the Rear Fog Lamp(s) Relay 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 voltage. If the circuit tests normal, replace the K9 BCM.

瀚慖f the test lamp is always OFF, test the control circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace

the K9 BCM.

5. If all circuits test normal, replace the E5 fog lamp-rear.

Repair Instructions

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

* Tail Lamp Replacement (See: Lighting and Horns/Tail Lamp/Service and Repair)

* 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 Descriptors

DTC B2545 01

- Backup Lamps Circuit Short to Battery

DTC B2545 02

- Backup Lamps Circuit Short to Ground

DTC B2545 04

- Backup Lamps Circuit Open

Diagnostic Fault Information

Circuit/System Description

When the engine is running and the transmission is placed in reverse gear, the transmission control module 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. Once the driver moves the gear selector out of the reverse position, a message is sent by the transmission control module via serial data