Idle Speed Control (ISC)

During start mode, ECU controls throttle position in accordance with coolant temperature sensor input.

After starting with idle switch activated (throttle closed), fast idle speed is controlled by coolant temperature input to ECU and engine RPM feedback to ECU. When idle switch is deactivated (throttle open), ISC motor moves to a preset position in accordance with coolant temperature sensor input.

Idle control increases idle speed when power steering oil pressure switch or A/C switch is turned on or when transmission is shifted from Neutral to Drive position (A/T). During deceleration, ISC motor delays closing of throttle valve to its normal idling position.