GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Buick 🢒 2006 🢒 Rendezvous - FWD 🢒 Accessories 🢒 Navigation Systems 🢒 DTC B2533

Circuit Description

The body control module (BCM) controls the operation of the fog lamps. When the park lamps are on, and the fog lamp switch is turned ON, the BCM grounds the control circuit of the fog lamps relay in order to illuminate the fog lamps.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC B2533 Front Fog Lamps Control Circuit High

Conditions for Running the DTC
    • Voltage supplied to the module is in the normal operating range, approximately 9-16 volts.
    • The front fog lamp feature is enabled.

Conditions for Setting the DTC
    • The BCM detects a short to battery positive voltage in the control circuit of the fog lamps relay when the fog lamps are commanded ON.
    • The condition is present for longer than 3 ms.

Action Taken When the DTC Sets

The BCM stores DTC B2533 in memory.

Conditions for Clearing the MIL/DTC
    • A current DTC B2533 clears when the BCM no longer detects a short to battery positive voltage in the control circuit of the fog lamps relay.
    • A history DTC B2533 clears after 100 consecutive ignition cycles when the condition is no longer present.
    • A DTC B2533 will clear when commanded by a scan tool.

Diagnostic Aids
    • If the DTC B2533 is a history DTC, the fault may be intermittent. Refer to Testing for Intermittent Conditions and Poor Connections .
    • An intermittent short to voltage in the following locations may cause an intermittent malfunction to occur:
       - The control circuit of the fog lamps relay
       - The fog lamps relay
       - The BCM

Step

Action

Yes

No

Schematic Reference: Fog 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 ON the ignition, with the engine OFF.
  3. With a scan tool, command the fog lamps relay ON and OFF.

Does the fog lamps 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 fog lamps relay.
  3. Turn ON the ignition, with the engine OFF.
  4. Connect a test lamp between the battery voltage circuit of the fog lamps relay coil and ground. Refer to Circuit Testing .

Does the test lamp illuminate?

Go to Step 4

Go to Step 7

4

  1. Connect a test lamp between the control circuit of the fog lamps relay and the battery voltage circuit of the fog lamps relay coil. Refer to Circuit Testing .
  2. With a scan tool, command the fog lamps relay ON and OFF .

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

Go to Step 8

Go to Step 5

5

Test the control circuit of the fog lamps relay for a short to battery positive voltage. Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

Go to Step 10

Go to Step 6

6

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

Did you find and correct the condition?

Go to Step 10

Go to Step 9

7

Replace the underhood fuse block. Refer to Testing for Intermittent Conditions and Poor Connections .

Did you complete the repair?

Go to Step 10

--

8

Replace the fog lamps relay. Refer to Relay Replacement .

Did you complete the replacement?

Go to Step 10

--

9

Replace the BCM. Refer to Control Module References for replacement, setup, and programming.

Did you complete the replacement?

Go to Step 10

--

10
  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