Antilock Brakes / Traction Control Systems: Testing and Inspection

ABS Indicator Malfunction

Diagnostic Instructions

1. Perform the Diagnostic System Check - Vehicle (Initial Inspection and Diagnostic Overview) prior to using this diagnostic procedure.
2. Review Strategy Based Diagnosis (Initial Inspection and Diagnostic Overview) for an overview of the diagnostic approach.
3. Diagnostic Procedure Instructions (Initial Inspection and Diagnostic Overview) provides an overview of each diagnostic category.

Circuit/System Description

The instrument panel cluster (IPC) momentarily illuminates the antilock brake system (ABS) indicator during the bulb check when the ignition is cycled ON. When the electronic brake control module (EBCM) detects a fault requiring ABS indicator ON, it sends a serial data message to the IPC to illuminate the ABS indicator.

Reference Information
Schematic Reference

Antilock Brake System Schematics ([1][2]Antilock Brakes / Traction Control Systems)
Connector End View Reference

Component Connector End Views (Connector Views)
Description and Operation

ABS Description and Operation (Description and Operation)
Electrical Information Reference

* Circuit Testing (Component Tests and General Diagnostics)
* Connector Repairs (Component Tests and General Diagnostics)
* Testing for Intermittent Conditions and Poor Connections (Component Tests and General Diagnostics)
* Wiring Repairs (Component Tests and General Diagnostics)

Scan Tool Reference

Control Module References (Programming and Relearning) for scan tool information

Circuit Verification

1. With a scan tool command the IPC display test ON and OFF. The ABS indicator should turn ON and OFF.

• If the ABS indicator does not turn ON and OFF when commanded, replace the IPC.

2. Replace the EBCM.

Repair Instructions

Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.

Control Module References (Programming and Relearning) for EBCM or IPC replacement, setup, and programming