Power Steering

DTC C056D (with HP5)

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle (Initial Inspection and Diagnostic Overview) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Initial Inspection and Diagnostic Overview) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Initial Inspection and Diagnostic Overview) provide an overview of each diagnostic category.

DTC Descriptor
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 µC Failure

DTC C056D 39
- ECU Hardware Performance Internal Electronic Failure

Circuit/System Description

The power steering control module (PSCM) continuously monitors the internal hardware within the module.

Conditions for Running the DTC

Ignition ON.

Conditions for Setting the DTC

The PSCM detects an internal hardware malfunction within the module.

Action Taken When the DTC Sets

* No Steering assist.
* The driver information center (DIC) displays the SERVICE POWER STEERING warning message.
* DTC is stored in memory.

Conditions for Clearing the DTC

* A current DTC will clear on the next malfunction free ignition cycle.
* A history DTC will clear after 40 consecutive malfunction free ignition cycles.

Reference Information
Schematic Reference

Power Steering Schematics (Electrical Diagrams)
Connector End View Reference

Component Connector End Views (Connector Views)
Description and Operation

Power Steering System Description and Operation (without HP5) (Description and Operation)Power Steering System Description and Operation (with HP5) (Description and Operation)
Electrical Information Reference

* Circuit Testing (Component Tests and General Diagnostics)
* Connector Repairs (Component Tests and General Diagnostics)
* Testing for Intermittent Conditions and Poor Connections (Component Tests and General Diagnostics)
* Wiring Repairs (Component Tests and General Diagnostics)

Scan Tool Reference

Control Module References (Programming and Relearning) for scan tool information

Circuit/System Testing

Verify that DTC C056D is not set.

If the DTC is set, replace the PSCM.

Repair Instructions

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

Control Module References (Programming and Relearning) for PSCM replacement, setup, and programming