| 摘要 |
There is provided a fail control apparatus for an automatic transmission, which, in the event of a friction element failure, is capable of coping with the failure by identifying a failed part without erroneous determination and within a short time. The set gear ratio of a designated gear position at the time of failure and the actual gear ratio are compared with each other to determine whether a friction element has failed, and an alternative gear position which enables a vehicle to start moving again is designated based on the determination result. In determining a failed friction element, one friction element disengaged or engaged due to failure is identified only when the designated gear position is the first speed gear position which is achieved by engaging one low clutch and a one-way clutch. It is therefore possible to determine the details of failure with accuracy and properly set an alternative gear position. On the other hand, when the designated gear position at the time of failure is other than the first speed gear position, in which a plurality of friction elements are engaged, one friction element which has failed is not identified, and it is therefore possible to quickly set an alternative gear position without the possibility of erroneous determination. |
