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). VIS valves 1 and 2 control vacuum modulators that 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).

Fig 1: Locating Variable Intake Manifold Solenoid Valve, Connector And Filter

Courtesy of KIA MOTORS AMERICA, INC.

Engine condition	VIS valve 1	VIS valve 2	Operation
Engine condition	Intake Manifold	Surge Tank	Operation
Low speed	Closed	Closed	Increasing engine performance in low engine speed by reducing intake interference among cylinders
Medium speed	Open or Closed	Open	Increasing intake efficiency
High speed	Open	Open	Minimizing intake resistance by shortening intake manifold length and increasing area of air entrance

Fig 2: Locating Variable Intake Manifold Solenoid Valve Opening And Closing Position

Courtesy of KIA MOTORS AMERICA, INC.