C0131

DTC C0131

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle Diagnostic System Check - Vehicle prior to using this diagnostic procedure.

* Review Strategy Based Diagnosis Strategy Based Diagnosis for an overview of the diagnostic approach.

* Diagnostic Procedure Instructions Diagnostic Procedure Instructions provides an overview of each diagnostic category.

DTC Descriptors

DTC C0131 00
- Antilock Braking System Pressure Circuit Malfunction

DTC C0131 4B
- Antilock Braking System Pressure Calibration Not Learned

Circuit/System Description

The electronic brake control module monitors the brake pressure sensor which is integral to the brake pressure modulator. The body control module monitors the brake pedal position sensor signal when the brake pedal is applied and sends a serial data message to the electronic brake control module indicating the brake pedal position. The electronic brake control module compares the brake pressure to the brake pedal position and uses this information for vehicle stability control.

Conditions for Running the DTC

DTC C0131 00

* Ignition ON.

* The brakes are applied.

DTC C0131 4B

* The brakes are not applied.

* Operating the vehicle at a speed greater than 10 km/h (7 mph).

Conditions for Setting the DTC

* The brake pressure is out of the specified range.

* The brake pressure sensor offset is out of the specified range.

* The brake pressure sensor supply voltage is less than 4.4 V or greater than 5.4 V.

Action Taken When the DTC Sets

* The ABS indicator turns ON.

* The traction control/stability control indicator turns ON.

* The electronic brake control module disables the antilock brake system, the traction control and stability control for the duration of the ignition cycle.

Conditions for Clearing the DTC

* When the condition for setting the DTC is no longer present.

* The history DTC will clear after 40 consecutive fault-free ignition cycles have occurred.

Note: During normal diagnostic and/or repair verification technicians may find that the ABS, Traction control and/or Stability control indicators may be ON with NO DTCs displayed by the electronic brake control module. Do not replace the electronic brake control module for this condition.

If the ABS, Traction control and/or Stability control indicators are ON with no DTCs set, perform the following steps:

1. Remove the key from the ignition, open and close the driver's door to turn off retained accessory power, and wait 60 seconds.

2. Ignition ON, if the ABS, Traction Control and/or Stability control indicators are still illuminated, operate the vehicle at speeds greater than 16 km/h (10 MPH) to complete the self test. The electronic brake control module should request all indicators to turn OFF.

3. If indicators remain ON with no DTCs set after the drive cycle, disconnect the battery for at least 60 seconds then reconnect the battery.

4. Operate the vehicle at speeds greater than 40 km/h (25 MPH), the electronic brake control module should request all the indicators to turn OFF.

Reference Information

Schematic Reference

Antilock Brake System Schematics [1][2]Antilock Brakes / Traction Control Systems

Connector End View Reference

Component Connector End Views Fuel Pump and Level Sensor Assembly - Primary

Description and Operation

ABS Description and Operation (Without F55) ABS Description and Operation (Without F55)ABS Description and Operation (With F55) ABS Description and Operation (With F55)

Electrical Information Reference

* Circuit Testing Circuit Testing

* Connector Repairs Connector Repairs

* Testing for Intermittent Conditions and Poor Connections Testing for Intermittent Conditions and Poor Connections

* Wiring Repairs Wiring Repairs

Scan Tool Reference

Control Module References Control Module References for scan tool information

Circuit/System Verification

Note: Diagnose all other stop lamp DTCs or Symptoms prior to performing this diagnostic procedure.

1. Ignition ON.

2. Verify that DTC C0277 or C0890 is not set.

• If either DTC is set
Refer to DTC C0277 or C0890 C0277.

• If either DTC is not set

3. Verify the brake pedal position sensor or the brake pedal is not binding causing residual brake pressure to be detected.

• If a condition is found

Repair or replace the applicable component.

• If a condition is not found

4. Verify the scan tool electronic brake control module Brake Pedal Position Sensor parameter changes between Active and Inactive when applying and releasing the brake pedal.

• If the parameter does not change
Refer to Symptoms - Lighting Symptoms - Lighting.

• If the parameter changes

5. Perform the Brake Pressure Modulator Valve Pressure Sensor Calibration Testing and Inspection

6. Verify that DTC C0131 does not set while operating the vehicle under the Conditions for Running the DTC.

• If DTC C0131 sets

1. Replace the Q5 brake pressure modulator.

2. Verify the DTC does not set while operating the vehicle within the Conditions for Running the DTC.

• If the DTC sets, replace the K17 electronic brake control module.

• If the DTC does not set

3. All OK.

• If DTC C0131 does not set

7. Engine Running.

8. Verify the scan tool Brake Pressure Sensor parameter is between 0.45-0.55 V when the brake pedal is not applied.

• If not between 0.45-0.55 V

1. Replace the Q5 brake pressure modulator.

2. Verify the DTC does not set while operating the vehicle under the Conditions for Running the DTC.

• If the DTC sets, replace the K17 electronic brake control module.

• If the DTC does not set

3. All OK.

• If between 0.45-0.55 V

9. Verify the scan tool Brake Pressure Sensor parameter is between 0.45-4.50 V with the brake pedal applied.

• If not between 0.45-4.50 V

1. Replace the Q5 brake pressure modulator.

2. Verify the DTC does not set while operating the vehicle under the Conditions for Running the DTC.

• If the DTC sets, replace the K17 electronic brake control module.

• If the DTC does not set

3. All OK.

• If between 0.45-4.50 V

10. All OK.

Repair Instructions

Perform the Diagnostic Repair Verification Verification Tests after completing the repair.

* Brake Pressure Modulator Valve Replacement Service and Repair

* Control Module References Control Module References for electronic brake control module replacement, programming and setup