Idle Speed/Throttle Actuator - Electronic: Description and Operation

Throttle Position Sensor (TPS)/Automatic Idle Speed (AIS) Motor:

The engine controller operates the Automatic Idle Speed (AIS) motor to maintain the proper idle speed. Inputs from the throttle position sensor, speed sensor, and coolant temperature sensor are used by the engine controller to calculate the proper idle speed. Various switches (brake, neutral/safety) are also used to provide input for the idle speed. The AIS varies the air portion of the air/fuel mixture via an air bypass in the throttle body. The AIS controls the amount of bypass air to adjust the idle speed, compensating for various engine loads and operating conditions. Deceleration stall is also prevented by increasing the airflow when the throttle is closed suddenly. The AIS motor is mounted on the throttle body.