EGR Control Solenoid: Description and Operation

The EGRC-solenoid valve responds to signals from the ECM. When the ECM sends an ON (ground) signal, the coil in the solenoid valve is energized.
A plunger will then move to cut the vacuum signal from the intake manifold to the EGR valve. When the ECM sends an OFF signal, the vacuum signal passes through the solenoid valve. The signal then reaches the EGR valve.