GM Service Manual Online
For 1990-2009 cars only

Circuit Description

The body control module (BCM) controls the backup lamp relay. The BCM grounds the backup lamp relay control circuit which energizes the backup lamp relay.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC B2552 Backup Lamps Control Circuit Low

Conditions for Running the DTC

Any of the following conditions may be present:

    • The transaxle is not in the reverse position.
    • The emergency vehicle interior lamp switch is enabled.
    • The ignition switch is in the OFF position.

Conditions for Setting the DTC

    • The BCM detects a short to ground or open in the backup lamp relay control circuit when it is not trying to energize the backup lamp relay.
    • The condition above must be present for more than 0.3 seconds.

Action Taken When the DTC Sets

The BCM stores DTC  B2552 in memory.

Conditions for Clearing the DTC

    • A current DTC B2552 will clear if the BCM no longer detects a short to ground or open in the backup lamp relay control circuit.
    • A history DTC B2552 will clear after 100 consecutive ignition cycles if the condition for the malfunction is no longer present.

Diagnostic Aids

    • If the DTC B2552 is a history DTC, the fault may be intermittent. Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems.
    • The following conditions may cause an intermittent malfunction to occur:
       - An intermittent short to ground or open in the backup lamp control circuit
       - The backup lamp relay coil is intermittently shorted to ground or open internally.
       - The BCM is intermittently shorted to ground or open internally.

Step

Action

Yes

No

Schematic Reference: Exterior Lights Schematics

Connector End View Reference: Master Electrical Component List in Wiring Systems

1

Did you perform the Diagnostic System Check - Vehicle?

Go to Step 2

Go to Diagnostic System Check - Vehicle in Vehicle DTC Information

2

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

Does the backup lamp relay turn ON and OFF with each command?

Go to Diagnostic Aids

Go to Step 3

3

  1. Turn OFF the ignition.
  2. Disconnect the backup lamp relay.
  3. Turn ON the ignition, with the engine OFF.
  4. Probe the backup lamp relay coil side battery positive voltage circuit with a test lamp that is connected to ground.

Does the test lamp illuminate?

Go to Step 4

Go to Step 10

4

  1. Connect a test lamp between the backup lamp relay coil side battery positive voltage circuit and backup lamp relay control circuit.
  2. With a scan tool, command the backup lamp relay ON and OFF.

Does the test lamp turn ON and OFF with each command?

Go to Step 8

Go to Step 5

5

Does the test lamp remain illuminated with each command?

Go to Step 7

Go to Step 6

6

Test the backup lamp relay control circuit for a short to battery positive voltage or an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 13

Go to Step 9

7

Test the backup lamp relay control circuit for a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 13

Go to Step 9

8

Inspect for poor connections at the backup lamp relay. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 13

Go to Step 11

9

Inspect for poor connections at the harness connector of the body control module (BCM). Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 13

Go to Step 12

10

Replace the I/P accessory wiring junction block - right. Refer to Instrument Panel Electrical Center or Junction Block Replacement - Right Side in Wiring Systems.

Did you complete the repair?

Go to Step 13

--

11

Replace the backup lamp relay. Refer to Relay Replacement in Wiring Systems.

Did you complete the replacement?

Go to Step 13

--

12

Replace the BCM. Refer to Control Module References in Computer/Integrating Systems for replacement, setup and programming.

Did you complete the replacement?

Go to Step 13

--

13

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

Does the DTC reset?

Go to Step 2

System OK