C0131

DTC C0131

Circuit Description

The master cylinder pressure sensor is located within the brake pressure modulator valve (BPMV). The master cylinder pressure sensor signal, to the electronic brake control module (EBCM), increases as hydraulic pressure in the front brake circuit increases.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC C0131 Antilock Brake System (ABS)/Traction Control System (TCS) Pressure Circuit

Conditions for Running the DTC

^ The ignition is ON.
^ The vehicle stability enhancement system (VSES) sensors have been successfully initialized or the message center has displayed the stability system disabled message due to an unsuccessful initialization attempt. Refer to ABS Description and Operation (W/JL4) ABS Description and Operation (W/O JL4) for a complete explanation of VSES sensor initialization.
^ The vehicle is being driven relatively straight and level at a speed greater than 36 km/h (23 mph).
^ The transmission is not shifted into neutral or low gear.
^ The parking brake is released.

Conditions for Setting the DTC

Any of the following conditions may cause the DTC to set:

^ The EBCM detects open master cylinder pressure sensor circuitry.
^ The EBCM detects shorted master cylinder pressure sensor circuitry.
^ The master cylinder pressure sensor self-test, which occurs at power-up, fails.
^ The zero-pressure signal voltage is not within an acceptable range.
^ The master cylinder pressure is not within an expected tolerance based on deceleration rate and other data available to the EBCM.

Action Taken When the DTC Sets

^ The EBCM disables the VSES.
^ The TCS operates with engine torque reduction only.
^ The stability indicator turns ON.

Conditions for Clearing the DTC

The conditions for setting the DTC are no longer present and you use the scan tool Clear DTCs function.

Diagnostic Aids

Thoroughly inspect connections or circuitry that may cause an intermittent malfunction. Refer to the following:

^ Testing for Electrical Intermittents
^ Testing for Intermittent Conditions and Poor Connections
^ Wiring Repairs
^ Connector Repairs

Test Description

The number below refers to the step number on the diagnostic table.
3. This step is required for vehicles equipped with a hydro-boost brake assist system only. If the vehicle being serviced has vacuum assisted brakes, proceed to step 4.

Step 1 - Step 7:

Step 8 - Step 9: