Intake Air Control Valve System
WARNING: This page is about a different car, the 1995 Toyota Avalon. However, it is still accessible from the selected car via links, so may be relevant.
NOTE:
Intake air control valve system may also be referred to as Acoustic Control Induction System (ACIS).
Engine Control Module (ECM) controls amount of airflow into intake manifold by use of an intake air control valve. Intake air control valve is located at end of air intake chamber. See Fig 1. Operation of intake air control valve system provides increased power in all speed ranges.
The ECM uses an engine RPM input signal and throttle position sensor input signal for determining intake air control valve system operation. Engine RPM input signal is provided by camshaft and crankshaft position sensors.
The ECM controls ground circuit for intake air control valve system Vacuum Switch Valve (VSV). The VSV controls vacuum supply from vacuum tank to the actuator which operates intake air control valve in air intake chamber.