C0450

DTC C0450

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) provides an overview of each diagnostic category.



DTC Descriptors
DTC C0450 00
- Steering Assist Control Solenoid Actuator Circuit




Circuit/System Description

The electronic brake control module (EBCM) commands current from negative 2-amps positive 3-amps to the variable effort steering (VES) actuator, depending on vehicle speed. At low speeds, 0-amps of current is commanded to the actuator and the steering gear receives full flow of power steering fluid causing less effort to steer vehicle. As vehicle speed increases, the amount of amps increases to the actuator causing fluid to bypass steering gear. This limits hydraulic assist to steering gear causing firm steering. The EBCM monitors and compares the VES Commanded Current and VES Feedback Current parameters to detect malfunctions in the VES System.


Conditions for Running the DTC

* The ignition is ON and engine ON.
* Ignition voltage is between 10.5-17 volts.



Conditions for Setting the DTC

An open, short to ground, or short to voltage in the VES actuator or the circuits to the actuator.


Action Taken When the DTC Sets

* DTC C0450 is stored in memory.
* VES output is disabled for the remainder of the ignition cycle.



Conditions for Clearing the DTC

* The condition for setting the DTC is no longer present and the DTC is cleared with a scan tool.
* The EBCM automatically clears the history DTC when a current DTC is not detected in 100 consecutive drive cycles.



Reference Information
Schematic Reference

Power Steering Schematics (Electrical Diagrams)
Connector End View Reference

Component Connector End Views (Connector Views)
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

1. Ignition OFF, disconnect the harness connector at the VES actuator.
2. Measure for 0 volts between the actuator control circuit terminal B and ground.

• If over the specified range, test the actuator control circuit terminal B for short to voltage. If the circuit tests normal, replace the EBCM.

3. Ignition ON, measure for 12 volts between the actuator control circuit and ground.

• If under the specified range , test the actuator control circuit for short to ground or open/high resistance. If the circuit tests normal, replace the VES actuator.




Component Testing

1. Ignition OFF, disconnect the VES actuator harness connector.
2. Measure for 1.6-3.1 ohms between the VES actuator terminals A and B.

• If not within the specified range, replace the VES actuator.

3. Measure for infinite ohms of resistance between each VES actuator terminal and the VES actuator housing.

• If less than the specified range, replace the VES actuator.




Repair Instructions

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

* Steering Gear Replacement (Service and Repair)
* Control Module References (Programming and Relearning) for EBCM replacement, setup, and programming