GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Buick 🢒 2005 🢒 Century 🢒 DTC 🢒 DTC B2553

Circuit Description

The body control module (BCM) controls the backup lamp relay. The BCM grounds the backup lamps relay control circuit energizing the backup lamp relay.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC B2553 Backup Lamps Control Circuit High

Conditions for Running the DTC
    • The transaxle must be in the reverse position.
    • The ignition switch must be in the RUN position.
    • The emergency vehicle interior lamp switch is not enabled.

Conditions for Setting the DTC
    • The BCM detects a short to battery positive voltage in the backup lamp relay control circuit when the BCM tries 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 B2553 in memory.

Conditions for Clearing the DTC
    • The BCM no longer detects a short to battery positive voltage in the backup lamp relay control circuit.
    • A history DTC B2553 will clear after 100 consecutive ignition cycles if the condition for the malfunction is no longer present.
    • The BCM receives a clear code command from the scan tool.

Diagnostic Aids
    • If the DTC B2553 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 battery in backup lamp relay control circuit.
       - The backup lamp relay coil is intermittently shorted to the battery.
       - The BCM is intermittently shorted to the battery.

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. Disconnected the backup lamp relay.
  3. Turn ON the ignition switch, with the engine OFF.
  4. Connect a test lamp between the control circuit of the backup relay and the coil side supply circuit of the backup relay.
  5. 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 5

Go to Step 4

4

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

Did you find and correct the condition?

Go to Step 9

Go to Step 6

5

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

Did you find and correct the condition?

Go to Step 9

Go to Step 7

6

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

Did you find and correct the condition?

Go to Step 9

Go to Step 8

7

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

Did you complete the replacement?

Go to Step 9

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8

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 9

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9
  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