C0131

DTC C0131

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle (Initial Inspection and Diagnostic Overview) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Initial Inspection and Diagnostic Overview) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Initial Inspection and Diagnostic Overview) provides an overview of each diagnostic category.

DTC Descriptor
DTC C0131 00
- Antilock Brake System (ABS) Traction Control System (TCS) Pressure Circuit

Circuit/System Description

The brake pressure sensor is integral to the brake pressure modulator valve assembly. The electronic brake control module (EBCM) monitors the brake pressure sensor supply voltage and the signal coltage.

The EBCM uses inputs from the brake pedal position sensor and the brake pressure sensor for more accurate control during a Vehicle Stability Enhancement System (VSES) event.

Conditions for Running the DTC

* System Voltage is above 9.6 volts.
* The vehicle speed is greater than 40 km/h (24 mph).

Conditions for Setting the DTC

* Sensor supply voltage is less than 4.5 volts or greater than 5.3 volts for more than 1 sec.
* Sensor signal voltage is less than 0.12 volts or greater than 3.2 volts for more than 1 sec.
* The EBCM sees the brake pedal is applied, and does not see the brake pressure increase when stopping.
* The EBCM sees the brake pressure increase, and does not see the brake pedal is applied when stopping.
* Signal is erratic.

Action Taken When the DTC Sets

If equipped, the following actions occur:

* The EBCM disables the Antilock Brake System (ABS), Traction Control System (TCS) Vehicle Stability Enhancement System VSES for the duration of the ignition cycle.
* The Traction Control indicator turns ON.
* The ABS indicator turns ON.
* The red brake warning indicator could turn ON.
* The driver information center (DIC) displays the Service Stability System message.

Conditions for Clearing the DTC

* The condition for setting the DTC is no longer present.
* The EBCM automatically clears the history DTC when a current DTC is not detected in 100 ignition cycles.

Reference Information
Schematic Reference

Antilock Brake System Schematics (without HP7) ([1][2]Antilock Brakes / Traction Control Systems)Antilock Brake System Schematics (HP7) ([1][2]Antilock Brakes / Traction Control Systems)
Connector End View Reference

Component Connector End Views (Connector Views)
Description and Operation

ABS Description and Operation (with LAT) (Description and Operation)
Electrical Information Reference

* Circuit Testing (Component Tests and General Diagnostics)
* Connector Repairs (Component Tests and General Diagnostics)
* Testing for Intermittent Conditions and Poor Connections (Component Tests and General Diagnostics)
* Wiring Repairs (Component Tests and General Diagnostics)

Scan Tool Reference

Control Module References (Programming and Relearning) for scan tool information

Circuit/System Verification

1. Verify that DTC C0161, C0277 or C0278 is not set.
• If DTC is set, refer to Diagnostic Trouble Code (DTC) List - Vehicle (Diagnostic Trouble Code Descriptions)

2. Apply and release the brake pedal. Verify the brake lamps operate properly.
• If the brake lamps do not operate properly, refer to Symptoms - Lighting Systems

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.
• If the parameter does not change between applied and released, replace the brake pressure modulator valve.

4. Clear the DTC and verify the DTC does not reset. If DTC resets, replace the EBCM.

Repair Instructions

Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.

* Brake Pressure Modulator Valve Replacement (Service and Repair)
* Control Module References (Programming and Relearning) for EBCM replacement, setup, and programming.