GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Pontiac 🢒 2006 🢒 GTO 🢒 Vehicle Control Systems 🢒 Vehicle DTC Information 🢒 ABS Indicator Inoperative

Circuit Description

The electronic brake control module (EBCM) turns ON the antilock brake system (ABS) indicator by grounding the ABS indicator control circuit. When the ignition switch is turned to the ON position, the EBCM turns ON the ABS indicator for 3 seconds for a bulb check. If the EBCM detects a malfunction, the ABS indicator will stay ON to warn the driver that the ABS 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 ABS indicator control circuit
    • An open, high resistance or short to ground in the instrument panel cluster (IPC) ignition voltage circuit
    • An open or high resistance in the EBCM ground circuits
    • An internal EBCM malfunction
    • An internal IPC malfunction

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

Test Description

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

  1. This step tests the EBCM ABS off warning lamp circuit for an open or high resistance.

    2.

  2. This step tests the IPC ignition voltage circuit for an open, high resistance or short to ground.

    3.

  3. This step tests the EBCM ground circuits.

Step

Action

Value(s)

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
  1. Turn OFF the ignition.
  2. Disconnect the electronic brake control module (EBCM) electrical connector.
  3. Turn ON the ignition, with the engine OFF.

Is the ABS indicator ON?

--

Go to Step 7

Go to Step 3

3
  1. Turn OFF the ignition.
  2. Disconnect the instrument panel cluster (IPC) harness connector.
  3. Measure the voltage between the ignition voltage circuits of the IPC and ground. Refer to Circuit Testing .

Does the voltage measure as specified?

Battery Voltage

Go to Step 4

Go to Step 5

4

Test the EBCM ABS OFF warning lamp circuit for an open or high resistance. Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

--

Go to Step 11

Go to Step 6

5

Test the IPC ignition voltage circuit for an open, high resistance or short to ground. Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

--

Go to Step 11

Go to Step 8

6

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

Did you find and correct the condition?

--

Go to Step 11

Go to Step 10

7

Inspect for poor connections at the harness connector of the EBCM. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .

Did you find and correct the condition?

--

Go to Step 11

Go to Step 9

8

Locate and repair the open, high resistance or short to ground in the ignition control relay circuits. Refer to Wiring Repairs .

Did you find and correct the condition?

--

Go to Step 11

--

9

Replace the EBCM. Refer to Electronic Brake Control Module Replacement .

Did you complete the replacement?

--

Go to Step 11

--

10

Replace the IPC. Refer to Instrument Cluster Replacement .

Did you complete the replacement?

--

Go to Step 11

--

11
  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