Idle Speed/Throttle Actuator - Electronic: Description and Operation

LOCATION

The automatic idle speed (AIS) motor is mounted to the back of the throttle body and is controlled by the engine controller.

OPERATION

The throttle body has an air bypass passage that provides air for the engine at idle (the throttle plate is closed). The AIS motor pintle protrudes into the air bypass passage and regulates air flow through it. Based on various sensor inputs, the engine controller adjusts engine idle speed by moving the AIS motor pintle in and out of the bypass passage. The AIS motor is positioned when the ignition key is turned to the On position.

A (factory adjusted) set screw is used to mechanically limit the position of the throttle body throttle plate. Never attempt to adjust the engine idle speed using this screw. All idle speed functions are controlled by the Engine Controller.