Toyota Jidosha Kabushiki Kaisha

Kiyoshi Kobayashi

Hideaki Otsubo

Toshiya Oishi

Yasushi Kobiki

Yoji Takanami

Tetsuro Shibata

A control device for a vehicular automatic transmission is provided which can preferably execute backpressure control of accumulators and torque-up control so as to minimize the occurrence of interference between learning on these controls during a gearshift operation. With the control device for the vehicular automatic transmission including the accumulators (and) operative to control a hydraulic pressure supplied to second and third clutches (Cand C) and a third brake (B), the backpressure control is executed for controlling a backpressure of the accumulators (and) during the gearshift operation while the torque-up control is executed for raising torque output from an engine (). Completion of learning on the backpressure control is determined when no completion of learning on the backpressure control is determined, learning on the backpressure control is executed with no execution of the torque-up control. Thus, no interference occur between learning on the backpressure control and the torque-up control.

Control device for vehicular automatic transmission

An ECT-ECU includes an abrupt turbine speed increase learning control circuit which prevents simultaneous release of both a frictional engagement element to be released and a frictional engagement element to be engaged, a tie-up learning control circuit which prevents simultaneous engagement of both the frictional engagement element to be released and the frictional engagement element to be engaged, a determination circuit that determines whether one of tie-up learning control and abrupt turbine speed increase learning control is necessary based on the turbine speed, and a control circuit that prohibits execution of the tie-up learning control unless the number of trips after the abrupt turbine speed increase learning control has been executed is at least equal to a predetermined number, when it has been determined that the tie-up learning control is necessary.

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Toyota, Japan

Kiyoshi Kobayashi