Variable Intake manifold Solenoid (VIS) valves are installed on the intake manifold (VIS Valve 1) and the surge tank (VIS Valve 2). These VIS valve 1 and 2 control vacuum modulators which activate valves in the intake manifold and the surge tank. These valves are opened or closed by ECM according to engine condition (Refer to below table).
Engine Condition | VIS Valve #1 (In-manifold) | VIS Valve #2 (Surge Tank) |
Low Speed | Open | Open |
Medium Speed | Close | Close |
High Speed | Close | Open |
High End Speed | Open | Open |
