| 摘要 |
PROBLEM TO BE SOLVED: To judge failure in any of frictional fastening elements fastened in the forward traveling range or a hydraulic adjusting means from the gear ratio sensed during the forward travel. SOLUTION: An automatic transmission 2 has a torque converter 3 and a shift gear mechanism 4, wherein the mechanism 4 is equipped with a plurality of frictional fastening elements including a front planetary gearing mechanism 41. rear planetary gearing mechanism 42 and a forward clutch 46, and these frictional elements are controlled by the oil pressure fed from a hydraulic adjusting device 50. The actual gear ratio of the shift gear mechanism 4 is sensed in the forward range, and judgement is passed that any appliance in the line pressure adjusting system or the forward clutch 46 has gone in failure if the sensed gear ratio is greater than the gear ratio of the first shift range. |
