| 摘要 |
PROBLEM TO BE SOLVED: To provide a control device of an automatic transmission, which establishes one of the shift speeds by occurring of slip in one of friction engagement elements in case of a failure in which engagement pressure is supplied to a hydraulic servo of the friction engagement element that is supposed to be disengaged, and which is capable of protecting the friction engagement element which slips in case of a failure. SOLUTION: The control device 1 of the automatic transmission sets an engagement pressure for each hydraulic servo in a normal operation so that none of friction engagement elements slips at each shift speed in the normal operation, and so that in case of a failure in which the engagement pressure is supplied to the hydraulic servo of the friction engagement element that is supposed to be disengaged in the normal operation, one of the friction engagement elements slips to establish one of the shift speeds. When a failure detection means 53 detects a failure state in which a gear ratio after a shift operation is a gear ratio of a shift speed different from a commanded shift speed, a release control means 56 releases the friction engagement element which has slipped. COPYRIGHT: (C)2011,JPO&INPIT |
