EGR Valve Position Sensor: Description and Operation

EGR System Operation (typical):

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 potentiometer supplying a signal to the ECM.

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.