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 C0131 00: Antilock Brake System Pressure Circuit

Circuit/System Description

The electronic brake control module (EBCM) uses input from the brake pressure sensor for more accurate control during a vehicle stability enhancement system (VSES) event.

Conditions for Running the DTC

    • Ignition ON.
    • Ignition voltage is greater than 10 volts.

Conditions for Setting the DTC

    • Pressure signal does not correlate to estimated pressure over time.
    • Brake Signal does not correlate to pressure signal.
    • Signal is erratic and changes faster than physically allowed.

Action Taken When the DTC Sets

    • The EBCM disables the ABS/traction control system (TCS)/vehicle stability enhancement system (VSES) for the duration of the ignition cycle.
    • A DIC message and/or a warning indicator may be displayed.

Conditions for Clearing the DTC

    • The condition for setting the DTC is no longer present.
    • The EBCM 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

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. Apply and release brake pedal. Verify brake lamps operate properly.
  2. If brake lamps do not operate properly, refer to Symptoms - Lighting.
  3. Ignition ON, observe the scan tool EBCM BPP signal parameter while applying and releasing the brake pedal. The reading should change between Applied and Released.
  4. If the parameter does not change between applied and release, replace the BPMV/EBCM assembly.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

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