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 electronic brake control module (EBCM) turns ON the Low Trac indicator by grounding the EBCM Low Trac indicator control circuit. When the EBCM detects that the traction control system is activated, the Low Trac indicator will illuminate.

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

  1. Verify DTC U0073, U0123, U0124, or U0126 are not set.
  2. If DTC U0073, U0123, U0124, or U0126 is set, refer to appropriate DTC.
  3. Using a scan tool, command the IPC display test ON and OFF. The Slip warning indicator should turn ON and OFF.
  4. If IPC does not perform as specified, replace the IPC.
    If IPC performs as specified, replace the BPMV/EBCM.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

    •  Brake Pressure Modulator Valve Replacement
    •  Control Module References for EBCM replacement, setup, and programming