EGR Control Solenoid: Description and Operation

Wiring Diagram:

The ECM operates a vacuum solenoid to control the EGR valve. The solenoid is normally closed. The ECM provides a ground path to energize the solenoid. This allows vacuum to flow to the EGR valve.

The ECM control of the EGR valve is based on the following inputs;

^ Engine coolant temperature above 25°F
^ TPS off idle
^ MAP