DESCRIPTION & OPERATION
The Variable Effort Steering (VES) system, also referred to as an Electronic Variable Orifice (EVO) steering system, varies the effort required to turn the steering wheel. VES system provides firmer steering (road) feel at higher vehicle speeds and improves directional stability. At low speeds and during parking VES system provides maximum assist.
As vehicle speed increases, VES decreases the amount of pump pressure applied to steering gear assembly to increase steering effort and improve steering feel by use of an Electronic Brake Control Module (EBCM).
The EBCM can detect a sudden turn (such as in an evasive maneuver) through input from steering wheel position sensor, Anti-Lock Brake System (ABS) Wheel Speed Sensors (WSS) and VES actuator.
VES system consists of an EBCM, VES actuator, steering wheel position sensor and 4 WSS. EBCM receives inputs from steering wheel position sensor and 4 WSS. Based on inputs from these sensors, EBCM varies the current to the VES actuator.
If VES actuator is disconnected, full pump pressure is allowed to flow through pump's high pressure line outlet, increasing fluid pressure to the steering gear. When VES actuator is controlled by the EBCM, fluid bypasses pressure line outlet and is routed back into pump, decreasing fluid pressure to the steering gear.
If a system fault occurs, EBCM sets a Diagnostic Trouble Code (DTC). DTC can be retrieved to diagnose fault. See DIAGNOSIS & TESTING .
| Component | Location |
|---|---|
| Data Link Connector (DLC) | Lower Left Hush Panel |
| EBCM | On Right Side Of Firewall, In Engine Compartment |
| Steering Wheel Rotation Sensor | At Base Of Steering Column |
| VES Actuator | At Pump Pressure Line Outlet |
| VES Actuator Module | (1) |
| Wheel Speed Sensors | Behind Each Brake Rotor |
| (1) VES actuator module is incorporated within EBCM. | |
| (1) | VES actuator module is incorporated within EBCM. |
VES STEERING SYSTEM ELECTRICAL COMPONENT LOCATIONS