Seed Control
WARNING: This page is about a different car, the 2004 Jeep Grand Cherokee. However, it is still accessible from the selected car via links, so may be relevant.
The PCM controls vehicle speed by operation of the speed control servo vacuum and vent solenoids. Energizing the vacuum solenoid applies vacuum to the servo to increase throttle position. Operation of the vent solenoid slowly releases the vacuum allowing throttle position to decrease. A special dump solenoid allows immediate release of throttle position caused by braking, cruise control turn off, shifting into neutral, exc excessive RPM (tires spinning) or ignition key off.