Variable Effort Steering System Operation

The Variable Effort Steering (VES) system varies the drivers effort required to steer the vehicle at different speeds. At low speeds, the system provides maximum power assist for ease of turning and parking maneuvers. At higher speeds, increased steering effort will provide the driver with firmer steering (road feel) and directional stability.
The VES system accomplishes this by reducing power steering fluid flow from the pump as the vehicle speed increases. When the vehicle is stationary, the system provides maximum fluid flow. As the vehicle's speed increases, fluid flow will decrease.
The power steering control module uses vehicle speed input from the Electronic Braking and Traction Control Module (EBTCM) to control the power steering fluid flow control valve actuator. The power steering fluid flow control valve actuator utilizes a pintle valve to control the fluid flow to the steering gear. In the event of a failure, the system will default to a full restriction. A full restriction will result in stiffer than normal steering at lower speeds.