Idle Speed Control (ISC) Motor

The ISC motor is an electrically driven actuator that changes the throttle stop angle by acting as a movable idle stop. It controls engine idle speed and maintains a smooth idle during sudden engine deceleration.

Throttle stop angle is determined by input information from the air conditioner compressor (on or off), transaxle (P or N), and throttle position sensor (wide open or closed).

For cold engine starting, the throttle is held open for a longer period to provide adequate engine warm-up prior to normal operation. When starting a hot engine, throttle open time is shorter.

Under normal engine operating conditions, engine idle is maintained at a pre-programmed RPM which may vary slightly due to engine operating conditions. Under certain engine deceleration conditions, the throttle is held slightly open.