Patent ID: 9651147
Date: 2017-05-16
CPC Classifications: F16H

Claim:
1. An apparatus for determining failure of an automatic transmission, comprising: input shafts that input rotation of a prime mover through a pair of clutches, the prime mover being mounted on a vehicle; an output shaft arranged in parallel to the input shafts; gears provided between the input shafts and the output shaft; gear engaging mechanisms that engage one of the gears to the input shafts and the output shaft to establish one of speeds corresponding to the engaged one of the gears; a line pressure-regulating valve that pressure-regulates hydraulic pressure discharged from an oil pump to a line pressure; pressure-regulating valves that pressure-regulate the line pressure regulated by the line pressure-regulating valve; select valves that selectively supply pressure regulated by the pressure-regulating valves to one of the pair of clutches and one of the gear engaging mechanisms; an operating state detector that detects an operating state of the gear engaging mechanisms; a pressure detector that detects the pressure regulated by the line pressure-regulating valve and the pressure-regulating valves; and a failure determiner that determines whether the pressure regulated by the line pressure-regulating valve is equal to or greater than a predetermined pressure based on an output of the pressure detector when one of the gear engaging mechanisms is supplied with the pressure so as to establish a speed, but the one of the gear engaging mechanisms is detected to be inoperative by the operating state detector, and the failure determiner determines that the line pressure-regulating valve has failed if the pressure regulated by the line pressure-regulating valve is determined to be less than the predetermined pressure, whereas the failure determiner determines one from among the pressure-regulating valves and select valves has failed by supplying the pressure to other of the gear engaging mechanisms and by detecting the operating state of the other gear engaging mechanism if the pressure regulated by the line pressure-regulating valve is determined to be equal to or greater than the predetermined pressure.