Electronic Variable Orifice (EVO) Actuator

The Electronic Variable Orifice (EVO) actuator is located on the power steering pump and contains a solenoid-operated pintle valve. Fluid leaving the pump passes through an orifice in the actuator tip. When the EVO actuator is powered by the SSPS control module, the pintle moves into the orifice and reduces the power steering fluid flow. As the vehicle speed increases, current from the SSPS control module increases, and the pintle blocks more and more of the orifice.