Idle Speed/Throttle Actuator - Electronic: Description and Operation

Idle System Control (ISC) Valve
The rotary solenoid type ISC valve is located in front of the intake air chamber and intake air bypassing the throttle valve is directed to the ISC valve through a passage.

In this way the intake air volume bypassing the throttle valve is regulated, controlling the engine speed.

The ECM operates only the ISC valve to perform idle-up and provide feedback for the target idling speed.