GM Service Manual Online
For 1990-2009 cars only

Circuit Description

The electronic brake control module (EBCM) turns ON the vehicle stability control (VSC) indicator by closing the VSC indicator control circuit. The VSC indicator is connected to the GAUGE fuse. This circuit has power when the ignition switch is in the ON or START positions. When the ignition switch is turned to the ON position, the EBCM turns ON the VSC indicator for 3 seconds for a bulb check. If the EBCM detects a malfunction, the VSC indicator will stay ON to warn the driver that the VSC is disabled and needs service.

Diagnostic Aids

Thoroughly inspect the wiring and the connectors. An incomplete inspection of the wiring and the connectors may result in a misdiagnosis, causing a part replacement with the reappearance of the malfunction.

The following are possible causes of the malfunction:

    • An open or high resistance in the VSC indicator control circuit
    • An internal EBCM malfunction
    • A malfunctioning instrument cluster panel assembly

If an intermittent malfunction exists, refer to Testing for Intermittent Conditions and Poor Connections .

Test Description

The number below refers to the step number on the diagnostic table.

  1. This step determines if the malfunction is caused by an internal EBCM malfunction.

Step

Action

Yes

No

Schematic Reference: Antilock Brake System Schematics

Connector End View Reference: Antilock Brake System Connector End Views

1

Did you perform the Diagnostic System Check - Vehicle?

Go to Step 2

Go to Diagnostic System Check - Vehicle

2

Do any of the other instrument cluster indicators or gages function?

Go to Step 3

Go to Gages Inoperative - All

3

  1. Turn OFF the ignition.
  2. Disconnect the electronic brake control module (EBCM) electrical connector.
  3. Ground the vehicle stability control (VSC) indicator control circuit.
  4. Turn ON the ignition, with the engine OFF.

Does the VSC indicator turn ON?

Go to Step 6

Go to Step 4

4

Test the VSC indicator control circuit for an open or high resistance. Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

Go to Step 7

Go to Step 5

5

Replace the instrument panel cluster assembly. Refer to Instrument Cluster Replacement .

Did you complete the replacement?

Go to Step 7

--

6

Replace the brake pressure modulator valve (BPMV). Refer to Brake Pressure Modulator Valve Assembly Replacement .

Is the repair complete?

Go to Step 7

--

7

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 2