| 摘要 |
PURPOSE:To detect abnormality of a frictional engagement device early by setting the rotating speed of an output member of a hydrodynamic gearing at the time of cancelling the frictional engagement device as reference rotating speed, and comparing the detected rotating speed to the reference rotating speed under the neutral range selected condition to judge abnormality. CONSTITUTION:An A/T control device 30 compares the rotating speed of an output shaft of a torque converter to be detected by a sensor 34 to the reference rotating speed of the case that each frictional engagement device is normally cancelled, under the condition that a neutral range of an automatic transmission 14 is selected by a selecting means, namely, under the condition that each frictional engagement device is cancelled, to judge abnormality. Namely, when the frictional engagement device is cancelled normally, the rotating speed of the output shaft and the reference rotating speed coincide with each other, but when drag of the frictional engagement device or the like is generated by peeling of the friction member or oil leakage, the real rotating speed of the output shaft becomes too low against the reference rotating speed at the time of stopping a vehicle, and it becomes too high or too low at the time coasting travelling in response to the speed, and judgement of abnormality is thus possible. Abnormality can be detected even at the time of usual use of a vehicle. |
