EGR Control Solenoid: Description and Operation

EGR Control Solenoid Valve:

PURPOSE
Regulates vacuum to the EGR valve, controlled by the ECM.

LOCATION
EGR mounted lift sensor and a vacuum control solenoid in the vacuum box

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

OPERATION
The ECM 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 supplying a signal to the ECM. If the EGR actual position differs from it's preferred position, the ECM cuts control solenoid power to reduce vacuum applied to the EGR valve.