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 C0136: Base Brake System Pressure Circuit

Circuit/System Description

The electronic brake control module (EBCM) monitors an internal input from the master cylinder pressure sensor to enhance Antilock Brake System (ABS) braking and vehicle stability if equipped.

Conditions for Running the DTC

The ignition is ON.

Conditions for Setting the DTC

    • When vehicle speed is more than 7 km/h (4 mph), the master cylinder pressure does not change for 30 seconds with the brake applied.
    • When vehicle speed is more than 10 km/h (6 mph), the master cylinder pressure signal is erratic.
    • Master cylinder pressure signal is out of range.
    • Master cylinder pressure is high for 5 seconds with the stop lamp switch signal OFF.

Action Taken When the DTC Sets

    • The EBCM disables traction control system (TCS) and vehicle stability enhancement system (VSES) for the duration of the ignition cycle.
    • The Stability Caution indicator turns ON.
    • The driver information center (DIC) displays the TRACTION FAILED message.
    • DIC displays the SERVICE STAB SYS message.
    • An ECE 13 response may occur.

Conditions for Clearing the DTC

    • The condition for the DTC is no longer present and the DTC is cleared with a scan tool.
    • The EBCM automatically clears the history DTC when a current DTC is not detected in 100 consecutive drive cycles.

Diagnostic Aids

The master cylinder pressure sensor is located internally in the BPMV and is not serviceable.

Reference Information

Schematic Reference

    •  Antilock Brake System Schematics
    •  Exterior Lights 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 for EBCM

Circuit/System Testing

Important: Inspect for brake lamp related DTCs and symptoms before diagnosing DTC C0136.

Important: A binding brake pedal or misadjusted brake switch can cause DTC C0136 to set. Correct any hydraulic brake symptoms before diagnosing this DTC. Refer to Symptoms - Hydraulic Brakes .

Disconnect the EBCM harness connector. Connect a test lamp between the stop lamp switch signal circuit and ground. Apply the brake.

If the test lamp does not illuminate but the center high mounted stop lamp (CHMSL) does illuminate, repair open in the stop lamp switch signal circuit.
If the test lamp and CHMSL does not illuminate, go to Symptoms - Lighting Systems .
If the test lamp and CHMSL illuminates, 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
    •  Symptoms - Lighting Systems