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 Low Traction indicator is controlled by the instrument cluster via serial data messages from the electronic brake control module (EBCM). When the traction control system (TCS) is active for 0.5 seconds, the EBCM commands the instrument cluster to flash the Low Traction indicator.

The EBCM sends a serial data message to the instrument panel cluster (IPC) to illuminate the Traction Control indicator when the EBCM has disabled the TCS due to a DTC. The Traction Control indicator will also turn ON during the instrument cluster bulb check. When the ignition switch is turned to ON, the Traction Control indicator will turn ON for approximately 3 seconds and then turn OFF.

Reference Information

Schematic Reference

Antilock Brake System Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

ABS Description and Operation

Electrical Information Reference

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

Scan Tool Reference

Control Module References for scan tool information

Circuit/System Verification

    Important: Diagnose all vehicle DTCs before using this diagnostic.

    The malfunction must be present during diagnosis in order to prevent unnecessary parts replacement.

  1. Ignition OFF for 5 seconds, ignition ON, observe that the traction off indicator functions by illuminating for 2 seconds then turns OFF
  2. If the traction OFF indicator does not illuminate, with the scan tool, select instrument panel special functions Display Test. Command the instrument panel lamps ON and OFF.
  3. Verify the TC lamp turns ON and OFF.
  4. If the TC warning lamp does not turn OFF, replace the IPC.
    If the TC warning lamp does turn OFF, replace the EBCM.

Repair Instructions

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

Repair Verification

Ignition OFF for 5 seconds, ignition ON, observe that the traction control off indicator functions by illuminating for 2 seconds then turns OFF. This is the bulb self test that operates upon every ignition key start cycle.