Description And Operation: Description
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 chart).
| 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 |