GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 HUMMER 🢒 2006 🢒 H3 🢒 Brakes 🢒 Park Brake 🢒 DTC B0525

Circuit Description

When the body control module (BCM) receives a left turn signal ON command from the turn signal switch, the BCM will apply voltage to the left turn signal indicator supply voltage circuit. The turn signal flasher, which is integrated within the BCM, will flash the left turn signal indicator lamp in the instrument panel cluster (IPC) simultaneously with the turn signal lamps.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC B0525 Left Turn Signal Circuit

Conditions for Running the DTC

The battery voltage must be between 9-16 volts.

Conditions for Setting the DTC

When the BCM receives a left turn signal command and the left turn signal indicator supply voltage circuit is open, shorted to ground, or shorted to voltage

Action Taken When the DTC Sets

The left turn signal indicator in the IPC will not operate or will remain always ON.

Conditions for Clearing the MIL/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 and current DTCs can be cleared using a scan tool.

Test Description

The numbers below refer to the step numbers on the diagnostic table.

  1. This step tests if battery positive voltage is constantly being applied to the supply voltage circuit.

    2.

  2. This step tests if a condition exists in the supply voltage circuit.

    3.

  3. This step tests if a condition exists in the ground circuit.

    4.

  4. After replacement of the IPC, you must calibrate the new cluster for proper operation.

    5.

  5. After replacement of the BCM, you must calibrate the new module for proper operation.

Step

Action

Yes

No

Schematic Reference: Fog Lights Schematics

Connector End View Reference: Lighting Systems Connector End Views , Instrument Panel, Gages, and Console Connector End Views , or Computer/Integrating Systems Connector End Views

1

Did you perform the Diagnostic System Check - Vehicle?

Go to Step 2

Go to Diagnostic System Check - Vehicle

2
  1. Turn ON the ignition, with the engine OFF.
  2. Activate the turn signals.

Do the exterior turn signals operate correctly?

Go to Step 3

Go to Symptoms - Lighting Systems

3
  1. Turn OFF the ignition.
  2. Remove the instrument panel cluster (IPC). Refer to Instrument Cluster Replacement .
  3. Turn ON the ignition, with the engine OFF.
  4. Connect a test lamp between the ground circuit and the left turn signal indicator supply voltage circuit at the IPC connector.
  5. Activate the inoperative turn signal ON and OFF.

Does the test lamp illuminate?

Go to Step 4

Go to Step 5

4

Does the test lamp remain illuminated with each command?

Go to Step 7

Go to Step 8

5

Test for a short to ground, open, or high resistance in the left turn signal indicator supply voltage circuit. Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

Go to Step 12

Go to Step 6

6

Test for an open or high resistance in the ground circuit. Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

Go to Step 12

Go to Step 9

7

Test the left turn signal indicator supply voltage circuit for a short to voltage. Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

Go to Step 12

Go to Step 9

8

Inspect for poor connections at the IPC. Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

Go to Step 12

Go to Step 10

9

Inspect for poor connections at the harness connector of the body control module (BCM). Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

Go to Step 12

Go to Step 11

10

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

Did you complete the replacement?

Go to Step 12

--

11

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

Did you complete the replacement?

Go to Step 12

--

12
  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