C0450
DTC C0450
Circuit Description
The variable effort steering (VES) system uses the electronic brake control module (EBCM) to control current to a bi-directional electromagnetic rotary actuator. The EBCM commands current from negative 3 amps to positive 3 amps to the actuator. At low speeds, less than approximately 24 km/h (15 mph), negative three amps of current is commanded, providing maximum assist to steering. As speed increases, increased (more positive) current is commanded, reaching zero amps at approximately 96 km/h (60). The EBCM commands positive current only during steering input at higher speeds, based on the above inputs and the vehicle calibration, which creates steering resistance.
DTC Descriptor
This diagnostic procedure supports the following DTC:
DTC C0450 Steering Assist Control Solenoid/Motor/Actuator Circuit
Conditions for Running the DTC
* Ignition voltage between 10.5-17 volts
* 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
* DTC C0450 is stored in memory.
* 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 ignition cycles.
Diagnostic Aids
The vehicle may need to be driven to view full VES Actuator Commanded and Actuator Feedback Data parameters.
Test Description
The numbers below refer to the step numbers on the diagnostic table.
2. This step tests if the Actuator Commanded and Actuator Feedback Current parameters are within specification in their active state.
3. Perform the VES test located under Special Functions. This test may indicate if the VES actuator is mechanically bound.
4. This step tests if the resistance of the VES actuator is within specification.
7. This step tests the control circuit of the VES actuator for a short to ground.
13. Perform the setup procedure after EBCM replacement. Programming and Relearning
