DTC P0661-00: Intake Manifold Tuning Valve Control Circuit Low: General Description

The VIS (Variable Intake System) is a device which varies the length of intake manifold to generate maximum power at certain RPM. The VIS lengthens intake manifold to improve the torque at low RPM when vehicle speed is low while it shortens intake manifold to raise torque at high RPM when vehicle speed is high. The PCM controls VIS (Variable Intake System) using RPM signal.