Patent ID: 8538647

Claim:
A control apparatus for an automatic transmission, for controlling a plurality of pressure regulating solenoid valves for regulating and controlling an engagement pressure to be supplied to or removed from each hydraulic servo of a plurality of friction engagement elements, and for determining the engagement pressure to be supplied to or removed from the each hydraulic servo in a normal operation so that none of the friction engagement elements slips at each shift speed in the normal operation, and so that in case of a failure in which the friction engagement element that is supposed to be disengaged in the normal operation is engaged, one of the friction engagement elements slips, and thus one of the shift speeds is established, the control apparatus characterized by comprising: a failure detecting portion that detects the failure when a gear ratio after a shift operation is a gear ratio of a shift speed different from a shift speed to be established; and a shift speed retaining portion that disengages the slipping friction engagement element, and retaining the shift speed that is different from the shift speed to be established, when the failure detecting portion detects the failure.