Function and operation principle

Variable Intake manifold Solenoid (VIS) valve is installed on the intake manifold. The VIS valve controls the vacuum modulator which activates a valve in the intake manifold. The PCM opens or closes this valve according to engine condition (Refer to below table).

Fig 1: Identifying Variable Intake Solenoid Valve Location

Courtesy of HYUNDAI MOTOR CO.

ENGINE CONDITION OPERATION CHART

Engine condition	VIS valve	Operation
Medium speed	Closed	Increasing engine performance in low engine speed by reducing intake interference among cylinders
Low/High speed	Open	Minimizing intake resistance by shortening intake manifold length and increasing area of air entrance

Fig 2: Identifying Variable Intake Solenoid Valve

Courtesy of HYUNDAI MOTOR CO.