Idle Speed Control (ISC)

During start mode the ECU controls the throttle position in accordance with coolant temperature 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 the ECU. When idle switch is deactivated (throttle open) ISC motor moves to a preset position in accordance with coolant temperature input.

When the air conditioner switch is turned to ON position or when the automatic transmission (if equipped) is shifted from Neutral to Drive, the ECU controls the RPM according to load on engine (RPM feedback control).

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 (automatic transmission only). Dashpot control delays closing of throttle valve to its normal idling position.