EGR System

An ECM controlled solenoid valve is used to control EGR valve function. This valve is located in the vacuum line to the EGR valve and is operated by the ECM in response to coolant temperature, throttle position and manifold pressure.

Under conditions of low coolant temperature, engine cranking, wide open throttle, or engine idle, the solenoid valve is energized, blocking vacuum to the EGR valve. At normal operating temperatures, the solenoid valve is de-energized, allowing normal EGR valve function.