If the difference between output torque output from an engine and load torque from drive wheels is large and torque input to a lockup clutch is large, since a value of lockup command pressure at which lockup engagement pressure in lockup end control becomes constant standby pressure is set to be high, fast release of the lockup clutch or racing of the engine is suppressed during the lockup end control. If torque input to the lockup clutch is small, the value of the lockup command pressure at which the lockup engagement pressure in the lockup end control becomes the constant standby pressure is set to be low, and a hydraulic pressure output period during which hydraulic pressure is output to the lockup clutch is set to be short.

An electronic control unit performs lockup clutch engagement control in the sequence of fast fill control, constant-pressure standby control and command pressure raising control, and starts the lockup clutch engagement control from that one of the fast fill control and the command pressure raising control which is later in sequence than the other, as a command pressure for a control oil pressure at a transition time point for making a transition to the lockup clutch engagement control rises, in making the transition to the lockup clutch engagement control during the lockup clutch release control. Therefore, when the command pressure for the control oil pressure is equal to or higher than a predetermined value that is needed to carry out packing for narrowing a pack clearance of a lockup clutch, the lockup clutch engagement control is started from the command pressure raising control.

Disclosed is a method of controlling a damper clutch through learning. A controller determines whether a driving condition of a vehicle is a condition where a predetermined selected fluid pressure value is desired. When necessary learning conditions are satisfied, the controller applies a control current for realizing a relevant fluid pressure to the solenoid valve. The controller updates the control current of the solenoid valve to an appropriate value based on response of the damper clutch. Thereafter, the controller controls the solenoid valve based on the updated control current.

A controller and a control strategy for a hybrid electric vehicle having a traction motor between an engine and an automatic transmission include maintaining a bypass clutch of a torque converter in an engaged position and applying a motor torque from a traction motor to the torque converter such that slip of the torque converter does not otherwise reach zero while the bypass clutch is maintained in the engaged position.

A transmission includes an input shaft coupled to a prime mover, a countershaft, main shaft, and an output shaft, with gears between the countershaft and the main shaft. A shift actuator selectively couples the input shaft to the main shaft by rotatably coupling gears between the countershaft and the main shaft. The shift actuator is mounted on an exterior wall of a housing including the countershaft and the main shaft. A controller controls the shift actuator utilizing an actuating pulse and an opposing pulse.

A lockup device (63) includes a lockup clutch (64) for establishing connection between a rotating body (44) of a torque converter (41) and a transmission shaft (55), a lockup control valve (70) that controls supply/discharge of pressurized oil from a hydraulic pump (69) to/from the lockup clutch (64), and a lockup oil passage (75) that introduces pressurized oil from the lockup control valve (70) to the lockup clutch (64). The lockup control valve (70) is arranged on an outer side face (18B) of an intermediate casing (18) in a position of radially overlapping the transmission shaft (55) in a radial direction of the transmission shaft (55). Further, a casing side oil passage (76) constituting the lockup oil passage (75) is formed as a linear oil passage that linearly extends in the radial direction of the transmission shaft (55) between the lockup control valve (70) and the transmission shaft side oil passage (77).

An electronic control unit starts shift initial oil pressure control after the completion of lockup initial oil pressure control when shift control is performed during the performance of lockup control, the electronic control unit starts shift initial oil pressure control after the completion of lockup initial oil pressure control. Besides, the electronic control unit places priority on the shift control and starts the lockup initial oil pressure control after the completion of the shift initial oil pressure control, when the lockup control is performed during the performance of the shift control. Therefore, the shift initial oil pressure control and the lockup initial oil pressure control are prevented from occurring at the same time when the shift control and the lockup control are performed at the same time.

A method and system are provided for operating a lockup clutch of a torque converter of a motor vehicle. The torque converter includes a pump rotatably driven by a drive unit, a rotatable turbine fluidly coupled to the pump and configured to drive an input shaft of a transmission, and a lockup clutch selectively engageable to non-fluidically couple the pump to the turbine to transmit torque from the drive unit to the transmission. The operation of the lockup clutch is controlled by the system in response to detecting that the motor vehicle is coasting.

A controller includes a control unit which is configured to execute a coast stop control. The coast stop control is configured to perform automatic stopping of the drive source while the vehicle is traveling, when a permitting condition is satisfied, the permitting condition including a condition that a speed ratio R of the variator is lower than a first threshold R1 while the lock-up clutch is in an engaged phase. The control unit is configured to prohibit execution of the coast stop control in a case in which an input-output rotation speed difference of the torque converter is equal to or more than a predetermined value when the lock-up clutch is in the engaged phase.

A CPU of a control device is configured to perform a specific cylinder fuel cutoff process of causing an internal combustion engine to operate such that supply of fuel to some cylinders out of a plurality of cylinders is stopped and supply of fuel to the other cylinders is maintained and a fastening force decreasing process of decreasing a fastening force of a lockup clutch of a torque converter. The CPU is configured to start the specific cylinder fuel cutoff process in a state in which the fastening force has been decreased through the fastening force decreasing process when the specific cylinder fuel cutoff process is performed in a state in which the internal combustion engine operates with a load.