• | 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. |
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
---|---|---|---|---|
Variable Effort Steering High Control | C0450 5A | C0450 5A | C0450 5A | -- |
Variable Effort Steering Low Control | C0450 5A | C0450 5A | C0450 5A | -- |
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 1A, 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.
• | Ignition ON. |
• | Engine OFF test -- Initial ignition ON, no engine RPM or vehicle speed present. |
• | Engine ON test -- If Engine OFF test passes, engine RPM and vehicle speed present. |
A short to voltage, short to ground, or open/high resistance is detected on the high control or low control circuit.
• | The ABS and red brake warning indicators illuminate. |
• | The driver information center (DIC) displays SERVICE STEERING SYSTEM. |
• | The VES system is disabled for the remainder of the ignition cycle. |
• | 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. |
Variable Effort Steering System Description and Operation
Control Module References for scan tool information
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%.
⇒ | If not the specified value, test the high control circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the EBCM. |
⇒ | If less than the specified value, test the low control circuit for a short to voltage or a short to ground. If the circuit tests normal, replace the EBCM. |
⇒ | If greater than the specified range, test the low control circuit for an open/high resistance. If the circuit tests normal, replace the EBCM. |
⇒ | If not within the specified range, replace the VES actuator. |
⇒ | If not the specified value, replace the VES actuator. |
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
• | Control Module References for EBCM replacement, setup, and programming |