EGR Control Solenoid: Description and Operation

EGR System Operation (typical):

PURPOSE
Regulates vacuum to the Exhaust Gas Recirculation (EGR) valve, controlled by the Engine Control Module (ECM).

OPERATION
The sensor uses a plunger operated potentiometer supplying a signal to the ECM. The solenoid bleeds off applied vacuum through a vent when powered. If the EGR actual position differs from it's preferred position, the ECM varies the duty cycle of the control solenoid to limit vacuum applied to the EGR valve.

CONSTRUCTION
The sensor uses a plunger operated electric solenoid, with a vacuum chamber mounted below to control engine vacuum.