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.

DTC Descriptor

DTC C0179: System Thermal High

Circuit/System Description

The electronic brake control module (EBCM) monitors Traction Control System (TCS) activation in order to calculate an estimate of the EBCM solenoid valve temperatures. In most cases high solenoid valve temperatures are caused by extended TCS activation. If the EBCM calculates that the solenoid valve temperatures are too high, the EBCM will temporarily suspend the TCS function until the solenoid valves cool.

Conditions for Running the DTC

The ignition is ON.

Conditions for Setting the DTC

The estimated solenoid coil temperature reaches the temperature limit.

Action Taken When the DTC Sets

    • The EBCM disables the Antilock Brake System (ABS)/TCS/Vehicle Stability Enhancement System (VSES) for the duration of the ignition cycle.
    • The ABS indicator turns ON.
    • The driver information center (DIC) displays the ABS system message.
    • The DIC displays the TRACTION FAILED system message.

Conditions for Clearing the DTC

    • After the solenoid valves have cooled the EBCM automatically re-enables TCS function.
    • The EBCM automatically clears the history DTC when a current DTC is not detected in 100 consecutive drive cycles.

Reference Information

Schematic Reference

Antilock Brake System Schematics

Connector End View Reference

Antilock Brake System 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

Circuit/System Verification

With the scan tool, observe the Brake Switch Status data parameter. Apply and release the brake pedal. The brake pedal switch status should change from OFF to ON.

Circuit/System Testing

  1. Most occurrences of this DTC are caused by excessive TCS activation or braking. Review with the customer to verify the conditions under which the DTC set.
  2. If vehicle operation caused this DTC to set, clear the DTC.
  3. Test drive the vehicle under normal conditions
  4. If the DTC resets under normal driving conditions, replace the EBCM/brake pressure modulator valve (BPMV).

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

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