Idle Speed/Throttle Actuator - Electronic: Description and Operation

The AIS motor, operated by the logic module or SMEC, adjusts the air portion of the air/fuel mixture through an air bypass on the back of the throttle body. Base idle is determined by the minimum air flow through the throttle body. The AIS motor opens or closes off the air bypass as needed according to engine loads or ambient conditions. The logic module or SMEC senses the change in air/fuel mixture and increases or decreases fuel accordingly to change engine idle. The AIS motor also prevents stalling during deceleration by increasing engine idle when the throttle is closed quickly.