GM Service Manual Online
For 1990-2009 cars only

Diagnostic Instructions

    • Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
    • Review Strategy Based Diagnosis for an overview of the diagnostic approach.
    •  Diagnostic Procedure Instructions provides an overview of each diagnostic category.

Circuit/System Description

The instrument panel cluster (IPC) illuminates the antilock brake system (ABS) indicator by supplying ground to the lamp. The electronic brake control module (EBCM) sends a serial data messages to the IPC, in order to command the indicator ON or OFF.

Reference Information

Schematic Reference

Antilock Brake System Schematics

Connector End View Reference

    •  Antilock Brake System Connector End Views
    •  Displays and Gages Connector End Views

Electrical Information Reference

    •  Circuit Testing
    •  Connector Repairs
    •  Testing for Intermittent Conditions and Poor Connections
    •  Wiring Repairs

Scan Tool Reference

Scan Tool Data List for EBCM

Circuit/System Testing

  1. With the scan tool, select instrument panel special functions Lamp Test. Command the instrument panel lamps ON. Verify ABS lamp illuminates.
  2. If the ABS lamp does not illuminate, replace the IPC.
  3. Replace the EBCM.

Repair Instructions

Always perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for EBCM and IPC replacement, setup, and programming