C12BE

DTC C012D, C120A, C128A, C128D, C12BC, C12BD, or C12BE

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 C012D 00
- Brake Boost Regulation Pressure Sensor Malfunction

DTC C128D 00
- ABS Boost Pressure Sensor Raw Offset Error

DTC C012D 01
- Brake Boost Regulation Pressure Sensor Short to Battery

DTC C12BD 00
- ABS Boost Pressure Sensor Circuit Short To Battery

DTC C012D 06
- Brake Boost Regulation Pressure Sensor Low Voltage/Open

DTC C12BC 00
- ABS Boost Pressure Sensor Circuit Open or Short To Ground

DTC C012D 11
- Brake Boost Regulation Pressure Sensor High Input

DTC C128A 00
- ABS Boost Pressure Sensor Offset Error

DTC C012D 5A
- Brake Boost Regulation Pressure Sensor Not Plausible

DTC C120A 00
- ABS Pump Pressure Performance

DTC C012D 0F
- Brake Boost Regulation Pressure Sensor Signal Erratic

DTC C12BE 00
- ABS Boost Pressure Sensor Erratic

Circuit/System Description

The electronic brake control module uses input from the boost pressure sensor for more accurate control during brake and vehicle stability enhancement system event. The boost pressure sensor is internal to the brake pressure modulator.

Conditions for Running the DTC

* Vehicle ON or Vehicle in Service Mode.
* The ignition voltage is greater than 10 V.

Conditions for Setting the DTC

C012D 00, C128D 00, C012D 11 or C128A 00
* Internal sensor failure is detected.
* The boost pressure sensor offset is out of range.

C012D 01 or C12BD 00

A short to battery is detected on the sensor signal circuit.

C012D 06 or C12BC 00

A short to ground or open is detected signal circuit.

C012D 5A or C120A 00

The boost pressure being commanded is not being achieved.

C012D 0F or C12BE 00

Signal is erratic and changes to fast.

Actions Taken when the DTC Sets

* The ABS indicator turns ON.
* The red brake indicator turns ON.
* The traction control/stability control indicator turns ON.
* The Service Brake Assist and Service StabiliTrak messages are displayed on the driver information center.
* The electronic brake control module disables the antilock brake system, the dynamic rear proportioning, the traction control system and the electronic stability program for the duration of the drive cycle.

Conditions for Clearing the DTC

* The condition for setting the DTC is no longer present.
* The history DTC will clear after 40 consecutive fault-free drive cycles have occurred.

Reference Information
Schematic Reference

Antilock Brake System Schematics [1][2]Antilock Brakes / Traction Control Systems
Connector End View Reference

Component Connector End Views Hybrid/EV Battery Pack X1
Description and Operation

ABS Description and Operation Description and Operation
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 Programming and Relearning for scan tool information

Circuit/System Verification

1. Vehicle in Service Mode.
2. Verify that no other electronic brake control module DTCs are set.

• If any other DTC is set
Refer to Diagnostic Trouble Code (DTC) List - Vehicle Diagnostic Trouble Code (DTC) List - Vehicle.

• If no other DTCs are set

3. Perform the Electronic Brake Control Module Learn procedure with a scan tool.
4. Verify none of the DTCs listed below are set:

* DTC C012D
* DTC C120A
* DTC C128A,
* DTC C128D
* DTC C12BC
* DTC C12BD
* DTC C12BE

• If any of the DTCs are set

5. Perform a brake hydraulic system test, refer to Brake Hydraulic and Assist System Diagnosis Brake Hydraulic and Assist System Diagnosis.

• If the brake hydraulic system test does not pass
Repair as necessary.

• If the brake hydraulic system tests normal

6. Replace the Q5 brake pressure modulator.
7. 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

8. All OK.

Repair Instructions

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

* Electronic Brake Control Module with Brake Pressure Modulator Valve Replacement Electronic Brake Control Module with Brake Pressure Modulator Valve Replacement
* Control Module References Programming and Relearning for electronic brake control module replacement, programming and setup