Idle Speed/Throttle Actuator - Electronic: Description and Operation

Throttle Body Assembly:

The Automatic Idle Speed (AIS) motor maintains idle speed under varying engine loads by controlling air flow into the intake manifold behind the throttle plate through a bypass passage. The Single Board Engine Controller (SBEC) maintains optimum idle speed by actuating the AIS motor to open or close the bypass opening according to a programmed response to inputs from various switches and sensors.