Abstract: An automatic transmission with an anti-creep control apparatus includes a torque converter connected to the engine, first and second friction elements, and a control unit. The first friction element is operated when the automatic transmission is put in a drive range. The second friction element performs to prevent a reverse rotation of an output shaft of the automatic transmission. The control unit executes an anti-creep control controls, controlling the second friction element to prevent a reverse rotation of an output shaft of the automatic transmission when the anti-creep control is executed, holds the engagement of the second friction element during a time period from the time when the anti-creep control is cancelled to the time when the first friction element is fully engaged, and disengages the second friction element thereafter.

Abstract: A lock-up control system for a torque converter, in a vehicle transmitting a driving torque of a prime mover to wheels via a power transmission unit including the torque converter which can establish direct coupling between an input element and an output element.

Abstract: An improved lockup control system for a lockup-type torque converter for automotive vehicle performs a coasting lockup control of a lockup clutch with minimized response delay of lockup releasing control and suppressed lockup releasing shock upon acceleration of the vehicle. The control system includes a controller that is operative when the driving condition of a vehicle as represented by the throttle valve opening and the vehicle speed is judged to belong to a lockup region. The controller reduces the differential pressure across the lockup clutch to a lower limit value within a range in which the clutch can be prevented from slips. Thus, when the vehicle is reaccelerated and the driving condition shifts out of the lockup region, the reduction amount of the differential pressure is minimized to mitigate the response delay in the lockup releasing control.

Abstract: An improved lockup control system for a lockup-type torque converter including a lockup clutch performs a lockup releasing control of the lockup clutch with a satisfactory response characteristic at any input torque of the torque converter without causing a lockup releasing shock. The control system includes a controller which is operative when the driving condition of a vehicle as represented by the throttle valve opening and the vehicle speed is judged to belong to a lockup releasing region, to reduce the differential pressure across the lockup clutch for disengaging the lockup clutch and thereby releasing the lockup. On such occasion, in the first place, the differential pressure is set to an initial differential pressure immediately before the lockup clutch begins to slip, depending upon the input torque of the torque converter at the instant of the lockup releasing command.

Abstract: A fail-safe hydraulic control system for an automatic transmission for a vehicle is provided.