Abstract: A normality detector includes a steering angle yaw rate calculator, a first difference calculator, a lateral G yaw rate calculator, a second difference calculator, and a normality determination section. The steering angle yaw rate calculator calculates a steering angle yaw rate. The first difference calculator calculates a first difference which is a difference between the steering angle yaw rate and an actual yaw rate. The lateral G yaw rate calculator calculates a lateral G yaw rate. The second difference calculator calculates a second difference which is a difference between the lateral G yaw rate and the actual yaw rate. The normality determination section determines that the yaw rate detector is in a normal state when the first difference falls within a first predetermined value and the second difference falls within a second predetermined value.

Abstract: 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.

Abstract: 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.