Patent ID: 8831922

Claim:
A failure sign detection apparatus comprising: an abnormality detection means to make a comparison between a failure detection parameter of a vehicle device mounted on a vehicle and a predetermined abnormality detection threshold, and make a determination whether there is an abnormality in the vehicle device based on a result of the comparison, wherein the predetermined abnormality detection threshold is set depending on a load of the vehicle by lowering a normal upper limit and raising a normal lower limit; a failure sign evaluation index calculation means to calculate, when the abnormality detection means determines that there is the abnormality in the vehicle device, an abnormality duration period over which the detected abnormality continues, and a parameter threshold difference indicative of a difference between the abnormality detection threshold and the failure detection parameter, and determine a product of the abnormality duration period and the parameter threshold difference as a failure sign evaluation index for evaluating a sign of failure of the vehicle device; a storage means to store the failure sign evaluation index calculated by the failure sign evaluation index calculation means; and a failure sign detection means to detect the sign of failure of the vehicle device based on the failure sign evaluation index calculated by the failure sign evaluation index calculation means and stored in the storage means.