C0450
DTC C0450
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 C0450 00
- Steering Assist Control Solenoid Actuator Circuit
Circuit/System Description
The electronic brake control module (EBCM) controls the variable effort steering (VES) actuator on the steering gear. As speed increases the EBCM commands the amperage to the actuator to a max of 1 amp, this closes the orifice and restricts fluid flow for a firm steering effort. At low speeds and parking lot maneuvers the orifice is normally open allowing maximum fluid flow for an easy steering effort. The EBCM monitors and compares the commanded and feedback parameters to detect malfunctions in the VES system.
Conditions for Running the DTC
* Ignition voltage
* Off state test-Initial ignition ON, no engine RPM or vehicle speed present.
* On state test-If off state test passes, engine RPM and vehicle speed present.
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
* The ABS and red brake warning indicators turn ON.
* The driver information center (DIC) displays the SERVICE STEERING SYSTEM warning message.
* The VES system is disabled for the remainder of the ignition cycle.
Conditions for Clearing the DTC
* A current DTC will clear when the malfunction is no longer present.
* A history DTC will clear after 100 consecutive ignition cycles with the malfunction no longer present.
Reference Information
Schematic Reference
Power Steering Schematics (Electrical Diagrams)
Connector End View Reference
Component Connector End Views
Description and Operation
Variable Effort Steering System Description and Operation (Variable Effort Steering System 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
Engine running, using a scan tool perform the VES Actuator test. Command the actuator while turning the steering wheel, the effort should increase when commanded between 10-100%.
Circuit/System Testing
1. Ignition OFF, disconnect the harness connector at the VES actuator.
2. Test for greater than 1 Mega ohm between the ground control terminal 1 and ground.
• If less than the specified range, test the ground control circuit for a short to ground. If the circuit tests normal, replace the EBCM.
3. Ignition ON, with a scan tool command the actuator ON 10%, verify less than 50 ohms.
• If greater than the specified range, test the ground control circuit for an open/high resistance. If the circuit tests normal, replace the EBCM.
4. Test for less than 2 volts between the voltage control terminal 2 and ground with the actuator command state at 0.
• If greater than the specified range, test the voltage control circuit for a short to voltage. If the circuit tests normal, replace the EBCM.
• If not the specified value, test the control circuit for a short to ground.
5. If all circuits test normal, test or replace the VES actuator.
Component Testing
Variable Effort Steering Actuator Test
1. Ignition OFF, disconnect the harness connector at the VES actuator.
2. Test for 5-10 ohms of resistance between the control terminals 1 and 2.
• If not within the specified range, replace the VES actuator.
3. Test for infinite resistance between each terminal and the VES actuator housing/case.
• If not the specified value, replace the VES actuator.
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
* Steering Gear Replacement (Service and Repair)
* Control Module References for EBCM replacement, setup, and programming