Park Brake

DTC C056D

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 provide an overview of each diagnostic category.

DTC Descriptors

DTC C056D 00
- Electronic Control Unit Hardware Malfunction

DTC C056D 34
- Electronic Control Unit Hardware RAM Malfunction

DTC C056D 35
- Electronic Control Unit Hardware ROM Malfunction

DTC C056D 36
- Electronic Control Unit Hardware EEPROM Performance/Malfunction

DTC C056D 37
- Electronic Control Unit Hardware Software Malfunction

DTC C056D 38
- Electronic Control Unit Hardware Supervision Software Malfunction

DTC C056D 39
- Electronic Control Unit Hardware Internal Malfunction

DTC C056D 3B
- Electronic Control Unit Hardware Internal Self - Test Malfunction

DTC C056D 3C
- Electronic Control Unit Hardware Internal Communication Malfunction

Circuit/System Description

The parking brake control module has an internal motor, apply actuator, release actuator, and temperature sensor. The parking brake control module also contains the logic for applying and releasing the parking brake when commanded by the park brake control switch. When the parking brake control module receives a signal from the switch the internal circuit board temperature is checked to verify it is within operating range before the control module performs the requested operation. The parking brake module will perform diagnostics on the modules internal hardware to verify it is functioning properly

Conditions for Running the DTC

Ignition OFF, ACCESSORY, or RUN mode.

Conditions for Setting the DTC

The parking brake control module detects an internal hardware malfunction.

Action Taken When the DTC Sets

DTC C056D 00, C056D 34, C056D 35, C056D 36, C056D 37, C056D 38, C056D 3B, or C056D 3C

* The parking brake is disabled.

* A message and/or a warning indicator may be displayed.

DTC C056D 39

* The parking brake is disabled, one release allowed.

* A message and/or a warning indicator may be displayed.

Conditions for Clearing the DTC

* The parking brake control module will clear the DTC after 40 consecutive ignition on/off cycles with at least one test pass in each ignition cycle and no test fail result.

* The condition for the DTC is no longer present.

* The latest software and calibrations are programmed into the parking brake control module.

Reference Information

Schematic Reference

Park Brake System Schematics [1][2]Electrical Diagrams

Connector End View Reference

Component Connector End Views Outside Rearview Mirror - Driver

Description and Operation

Electronic Parking Brake Control Module Description 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 Control Module References for scan tool information

Circuit/System Verification

1. Ignition ON.

2. Verify DTC C056D 36 is not set.

• If DTC C056D 36 is set

1. Program the K83 parking brake control module. Refer to Electronic Parking Brake Control Module Programming and Setup Testing and Inspection.

2. Ignition ON. Apply and release the park brake.

3. Verify the DTC is not set.

• If the DTC is set, replace the K83 parking brake control module.

• If the DTC is not set

4. All OK.

• If DTC C056D 36 is not set

3. Perform the Parking Brake Actuator DTC Reset procedure with a scan tool for the parking brake control module.

4. Verify DTC C056D is not set.

• If DTC C056D is set
Replace the K83 parking brake control module.

• If DTC C056D is not set

5. All OK.

Repair Instructions

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

Control Module References Control Module References for parking brake control module replacement, programming and setup.