ACIS Control Circuit: Description
This circuit opens and closes the Intake Air Control Valve (IACV) in response to the engine load in order to increase the intake efficiency (ACIS: Acoustic Control Induction System).
When the engine speed is between 2200 and 4100 rpm and the throttle valve opening angle is 60° or more, the ECM supplies current to the VSV (ON status), so the IACV will close. Besides that condition, the VSV is usually OFF and the IACV is open.