Steering Control Module: Description and Operation

The control module contains a microprocessor which analyzes the vehicle speed sensor input and the steering wheel rotation sensor input continuously. With this information, the microprocessor controls the power steering control valve actuator, thereby regulating the fluid flow from the power steering pump.
^ At low vehicle speeds of 8 km/h (5 mph) or less, the actuator valve is controlled to provide full power steering pump flow for full power steering assist.
^ At higher vehicle speeds, the power steering is controlled to reduce power steering pump flow and to reduce the power steering assist.
^ For evasive maneuvering at high speeds (steering wheel rotation rate greater than 15 rpm), the power steering control valve actuator is controlled to increase the power steering pump flow, thereby increasing power steering assist.
^ The electronic variable orifice (EVO) is designed to provide full assist in the event of a component failure or system malfunction.