Air Intake 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.
The air cleaner filter element sub-assembly is equipped with 2 inlets, one of which is opened or closed by the air intake control valve (intake air surge tank assembly). This system reduces intake noise and increases engine power at low-to-high engine speed ranges.
When the engine is operating in the low-to-mid speed range, this control operates the air intake control valve to close one of the air cleaner filter element sub-assembly inlets. When the engine speed is more than 3600 rpm and the opening angle of the throttle valve is more than 60°, the ECM activates the vacuum switching valve (for AICS) and opens the air intake control valve.