Idle Speed/Throttle Actuator - Electronic: Description and Operation

The ISC actuator installed to the throttle body consists of DC motor, gears, plunger, closed throttle position (CTP, idle) switch, etc. According to the signal from ECM, how much the plunger projects varies. (The ISC actuator controls the minimum throttle valve opening according to signals from ECM.) The closed throttle position (idle) switch consisting of hall integrated circuit, magnet and spring detects whether the plunger of the ISC actuator contacts the throttle lever screw or not and transmits it as ON/ OFF signal to ECM.
- CTP (Idle) switch ON: when plunger of ISC actuator is in contact with throttle lever screw
- CTP (Idle) switch OFF: when plunger is apart from throttle lever screw

CAUTION: The ISC actuator and throttle lever screw are factory adjusted precisely. The ISC actuator must not be removed from the throttle body and it must not be disassembled under any circumstances. The throttle lever screw must not be removed or adjusted, either.