A control section includes a first turning direction estimating mechanism for estimating a first turning direction from a sign of the first yaw rate when an absolute value of the first yaw rate is a first threshold value or more, a second turning direction estimating mechanism for estimating a second turning direction from a sign of a difference between the second yaw rate and the second threshold value when the second yaw rate is not less than or not more than the second threshold value, a vehicle turning direction judging mechanism for judging that the direction when the first and second turning directions are the same is a turning direction of the vehicle and an abnormality judging mechanism for judging that the yaw rate sensor is abnormal when the turning direction and the direction of the actual yaw rate differs from each other.