GM Service Manual Online
For 1990-2009 cars only

Circuit Description

When the body control module (BCM) receives a class 2 signal from the power control module (PCM) indicating the gear selector is in the REVERSE position, the BCM applies battery positive voltage to the backup lamps voltage supply circuit. The backup lamps are grounded at G302.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC B2545 Backup Lamps Circuit

Conditions for Running the DTC

The battery voltage must be between 9-16 volts.

Conditions for Setting the DTC

DTC B2545 is set when the backup lamps supply voltage circuit is shorted to ground or opened.

Action Taken When the DTC Sets

The backup lamps will not operate.

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.
    • History DTCs can be cleared using a scan tool.

Diagnostic Aids

Perform a visual inspection for loose or poor connections at all related components. Refer to Testing for Intermittent Conditions and Poor Connections .

Step

Action

Yes

No

Schematic Reference: Exterior Lights Schematics

Connector End View Reference: Master Electrical Component List

1

Did you perform the Diagnostic System Check - Vehicle?

Go to Step 2

Go to Diagnostic System Check - Vehicle

2

  1. Install a scan tool.
  2. Turn the ignition to the ON position, with the engine OFF.
  3. With a scan tool, command the backup lamps ON and OFF.

Do the backup lamps turn ON and OFF with each command?

Go to Diagnostic Aids

Go to Step 3

3

Test the backup lamps voltage supply circuit for a short to ground or an open. Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

Go to Step 5

Go to Step 4

4

Replace the body control module (BCM) . Refer to Control Module References for replacement, setup, and programming.

Did you complete the replacement?

Go to Step 5

--

5

  1. Use the scan tool in order to clear the DTCs.
  2. Operate the vehicle within the Conditions for Running the DTC.

Does the DTC reset?

Go to Step 2

System OK