GS300, GS430, Is300, LS430 & SC430
WARNING: This page does not describe the selected car, but rather 9 other vehicles, including the 2003 Lexus SC 430, 2003 Lexus RX 300, 2003 Lexus LX 470, 2003 Lexus LS 430, and 2003 Lexus IS 300. However, it is still accessible from the selected car via links, so may be relevant.
ACIS is a variable induction system that improves low speed engine performance by increasing length of intake runners in air intake chamber. Engine Control Module (ECM) uses various input signals for determining intake air control valve system operation.
ECM controls ground circuit for ACIS Vacuum Switching Valve (VSV). VSV controls vacuum supply from vacuum tank to ACIS actuator. ACIS actuator opens and closes an intake air control valve, which increases length of intake runners. For Intake Air Control Valve (IACV) location, see AIR INDUCTION SYSTEMS in appropriate SYSTEM & COMPONENT TESTING article.