Idle Speed Control (ISC) Solenoid

The ISC solenoid, located on side of throttle body, by-passes air around throttle valve directly into the intake manifold. Air is allowed to pass through ISC solenoid when it is energized by the ECM. Solenoid is energized whenever idle speed drops to less than desired RPM due to engine load (i.e. electrical, A/C, P/S, A/T in Drive, etc.). ISC solenoid is also energized each time engine is started, or during periods of deceleration to compensate for rich mixtures caused by a fully closed throttle.