Patent ID: 7308871

Claim:
A control apparatus for a variable valve apparatus which continuously varies a lift amount and an operating angle of an engine valve of an internal combustion engine due to varying an angle of a control shaft by means of a motor, the control apparatus comprising: an angle sensor configured to detect the angle of the control shaft; a first control unit including a drive circuit for driving the motor, and a CPU capable of receiving a signal from the angle sensor and another signal indicating a target angle of the control shaft and of outputting a control signal to the drive circuit; a power supply controlling circuit capable of controlling the supply of power from a power supply to the drive circuit; and a second control unit capable of computing the target angle of the control shaft to output the target angle after being computed to the CPU, and of receiving the signal detected by and outputted from the angle sensor to thereby diagnose, from the target angle and the signal from the angle sensor, whether or not the first control unit is failed, the second control unit controlling the power supply controlling circuit to shut off of the power supply to the drive circuit when it is determined, by diagnosing, that the first control unit is failed.