EGR Control Solenoid: Description and Operation
EGR Solenoid Circuit:
The EGR control valve is a duty-cycle type solenoid. It has a valve that opens and closes the vacuum source line to atmosphere many times per second. This allows only a certain amount of ported vacuum to be applied to the EGR valve, thereby controlling the amount of EGR operation. The ECU opens and closes the negative circuit and the control relay supplies the positive circuit.