Idle Speed Control Solenoid

ISC Solenoid Valve Operation:

The Idle Speed Control (ISC) valve opens and closes an air bypass passage in the throttle body. The ECM controls the ISC valve according to input signals from various sensors and switches. The ISC automatically compensates for engine load changes and adjusts the idle air flow. If a sudden change in throttle opening takes place (deceleration), bypass air is increased when the throttle valve is opened, and gradually decreases when it closes.