Antilock Brake System

DTC C056D

Diagnostic Instructions

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

DTC Descriptor

DTC C056D 00

Electronic Control Unit Hardware Malfunction

DTC C056D 39

Electronic Control Unit Hardware Internal Malfunction

DTC C056D 3B

Electronic Control Unit Hardware Self-Test Malfunction

Circuit/System Description

The internal fault detection is handled inside the control module. No external circuits are involved.

Conditions for Running the DTC

Ignition ON

Conditions for Setting the DTC

In internal hardware failure is detected.

Action Taken When the DTC Sets

- The electronic brake control module (EBCM) disables the ABS, traction control, and stability control for the duration of the ignition cycle.
- The ABS indicator turns ON.
- The traction control/stability control-active indicator turns ON.

Conditions for Clearing the DTC

- A current DTC clears when the diagnostic runs and passes.
- The EBCM will turn OFF the indicators and enable the system functions in the next ignition cycle.

Diagnostic Aids

A newly replaced EBCM can set one or more DTC on its initial ignition ON cycle.

Reference Information

Schematic Reference

Antilock Brake System Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

ABS Description and Operation

Electrical Information Reference

- Circuit Testing
- Connector Repairs
- Testing for Intermittent Conditions and Poor Connections
- Wiring Repairs

Scan Tool Reference

Control Module References for scan tool information

Circuit/System Verification

1. Verify that DTC C056D is not set.
2. If the DTC is set in a control module that can be programmed, program the control module. If the DTC resets, replace the control module that set the DTC.
3. If the DTC is set in a control module that cannot be programmed, replace the control module that set the DTC.
4. If the DTC is set in a sensor, replace the sensor that set the DTC.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for module or sensor replacement, programming and setup