ACIS Control Circuit [12/2015 - 08/2016]: Description
WARNING: This page is about a different car, the 2016 Toyota Sienna. However, it is still accessible from the selected car via links, so may be relevant.
This circuit opens and closes the intake air control valve (intake air surge tank assembly) in response to changes in the engine load in order to increase the intake efficiency using the acoustic control induction system.
When the engine speed is between 0 and 4300 rpm and the throttle valve opening angle is 60° or more, the ECM supplies current to the actuator (on status), to close the intake air control valve. Under other conditions, the VSV is usually off and the intake air control valve is open.