Patent ID: 7481734

Claim:
A hydraulic control apparatus of a vehicular automatic transmission, comprising: a plurality of hydraulic friction engagement devices that are selectively engaged and released to establish a plurality of forward speed change stages of different speed change ratios, wherein a predetermined forward speed change stage is achieved through engagement of predetermined friction engagement devices of the plurality of friction engagement devices; an engagement oil pressure state determination portion that determines a state of engagement oil pressure of one of the predetermined friction engagement devices; a speed change stage non-establishment determination portion that determines that a predetermined speed change stage corresponding to a predetermined shift output is not established; and an identification portion that identifies a friction engagement device having a bad engagement that is a cause of non-establishment of the speed change stage based on the state of engagement oil pressure determined by the engagement oil pressure state determination portion if it is determined by the speed change stage non-establishment determination portion that a predetermined speed change stage corresponding to the predetermined shift output is not established.