EGR Control Solenoid: Description and Operation

EGR System Operation (typical):

The computer controlled portion of the EGR system consists of an EGR mounted lift sensor and a vacuum control solenoid in the vacuum box. The ECU contains memories for optimum EGR lift during various conditions. It reads actual EGR position from the lift sensor. The sensor uses a plunger operated potentiometer supply a signal to the ECU. The solenoid bleeds off applied vacuum through a vent when powered. If the EGR actual position differs from it's preferred position, the ECU varies the duty cycle of the control solenoid to limit vacuum applied to the EGR valve. For additional information on the EGR system, refer to EMISSION CONTROLS.