Description And Operation: Description

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 ECM opens or closes this valve according to engine condition (Refer to below table).

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ENGINE CONDITIONS AND OPERATIONS

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 1: Checking Variable Intake Manifold Solenoid Speed (Closed And Open)

Courtesy of HYUNDAI MOTOR AMERICA