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 34
- ECU Hardware Performance RAM Failure

DTC C056D 35
- ECU Hardware Performance ROM Failure

DTC C056D 36
- ECU Hardware Performance EEPROM Failure

DTC C056D 37
- ECU Hardware Performance watchdog/safety uC Failure

DTC C056D 39
- ECU Hardware Performance Internal Electronic Failure

DTC C056D 3C
- ECU Hardware Performance Internal Communications Failure

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

* The electric parking brake is disabled.
* A message and/or a warning indicator may be displayed.

Conditions for Clearing the DTC

* The parking brake control module clears the history DTC when a current DTC is not detected in 40 ignition cycles.
* 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 (Connector End Views By Name)
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 (Programming and Relearning) for scan tool information

Circuit/System Verification

1. Verify DTC C056D 36 is not set.

• If DTC is set, perform the Electronic Parking Brake Control Module Programming and Setup (Testing and Inspection).

2. With a scan tool , perform the Parking Brake Actuator DTC Reset procedure. Verify DTC C056D is not set.

• If the DTC is set, replace the K83 Parking Brake Control Module.

Repair Instructions

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

Control Module References (Programming and Relearning) for parking brake control module replacement, setup, and programming.