GM Service Manual Online
For 1990-2009 cars only

Circuit Description

The instrument panel cluster (IPC) turns the ABS Indicator on during the IPC bulb check for approximately 3 seconds when the ignition switch is turned to the ON position. If the EBCM sets a diagnostic trouble code (DTC) the EBCM sends the IPC the command to turn the ABS indicator on.

Diagnostic Aids

    • It is very important that a thorough inspection of the wiring and connectors be performed. Failure to carefully and fully inspect wiring and connectors may result in misdiagnosis, causing part replacement with reappearance of the malfunction.
    • Thoroughly inspect any circuitry that may be causing the complaint for the following conditions:
       - Backed out terminals
       - Improper mating
       - Broken locks
       - Improperly formed or damaged terminals
       - Poor terminal-to-wiring connections
       - Physical damage to the wiring harness
    • The following conditions may cause an intermittent malfunction:
       - A poor connection
       - Rubbed-through wire insulation
       - A broken wire inside the insulation
    • If an intermittent malfunction exists refer to Inducing Intermittent Fault Conditions in Wiring Systems.

Test Description

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

  1. Checks if the instrument panel cluster has the ability to turn the ABS indicator off or if the EBCM is sending an incorrect command to turn the ABS indicator on.

Step

Action

Yes

No

Schematic Reference: Antilock Brake System Schematics Connector End View Reference: Instrument Panel, Gages, and Console Connector End Views

1

Did you perform the ABS Diagnostic System Check?

Go to Step 2

Go to Diagnostic System Check - ABS

2

Using a scan tool in the Instrument Panel Cluster Special Functions attempt to turn off the ABS indicator.

Did the ABS indicator turn off?

Go to Step 3

Go to Step 4

3

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

Is the replacement complete?

Go to Step 5

--

4

Replace the instrument panel cluster. Refer to Instrument Cluster Replacement in Instrument Panel, Gages and Console.

Is the replacement complete?

Go to Step 5

--

5

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 2