It is possible to suppress fluctuations of an air intake amount when the open degree of an air intake control valve is unknown. An engine includes an impulse valve common to all the cylinders arranged in the engine. The impulse valve is arranged in a communicating tube provided at the downstream side of a serge tank. An ECU executes impulse valve drive control. In the control, the ECU judges whether a rotation angle sensor which detects the open degree of the impulse valve has failed. If it is judged that the rotation angle sensor has failed, the ECU controls a drive motor and a drive circuit for driving a valve body so that a valve body of the impulse valve rotates inside the communicating tube. Here, the rotor of the drive motor which defines the rotation speed of the valve body has an rpm which is set in accordance with the mechanical rpm NE of the engine.