Systems and methods for improving operation of a driveline disconnect clutch for a hybrid vehicle shifting are presented. In one example, pressure of a working fluid supplied to the driveline disconnect clutch is adjusted in response to a rate of change in accelerator pedal position. Further, pressure of the working fluid may be decreased responsive to selected operating conditions.

In order to pre-stage a clutch piston in preparation for clutch engagement, a controller commands a high current to a Casting Integrated Direct Acting Solenoid (CIDAS) valve. This staging is performed in two distinct phases wherein the current is higher in the first phase than in the second phase. Staging the piston in this manner reduces the staging time and reduces the variability of the staging time. The duration of the first phase may be adjusted based on a number of parameters including, the length of a preceding engine off period, the number of clutch applications since the engine off period, a fluid temperature, and a length of time since a preceding engagement of the clutch.

A method of preventing a vehicle clutch from sticking includes a wear compensation actuation step of actuating a wear compensation device in conjunction with engagement actuation of a clutch actuator after an ignition is turned off when an actuation condition of the wear compensation device is satisfied, and a clutch control step of controlling a clutch position so that the clutch position returns to a disengaged state of the clutch actuator by reactuating the wear compensation device, when a clutch position based on an amount of variation in an actuation length of the actuation rod fails to return to the disengaged state of the clutch actuator during returning of the engaged clutch actuator.

A system and method for operating a vehicle equipped with an automatic stop and start system is disclosed. The vehicle includes an internal combustion engine, an automatic transmission and a fluid launch device with an impeller disconnect clutch. A controller may initiate an automatic stop or start of the engine under certain operating conditions. During an engine start/stop event, the engine is automatically shut down and the impeller clutch of the fluid launch device may be disengaged to decouple the engine and transmission from the driveline to provide for improved fuel economy and reduced emissions.

A method for determining a connection state of an engine clutch includes: a stroke sensing operation of sensing, by a controller, a change of an actuator stroke of the engine clutch; a first pressure comparing operation of determining whether or not an actuator pressure of the engine clutch exceeds a first set pressure and is then changed to below the first set pressure when the actuator stroke is increased; a torque comparing operation of comparing transfer a torque of the engine clutch with a set torque when the actuator pressure exceeds the first set pressure and is then operated to below the first set pressure; and an open determining operation of determining that the engine clutch is in an open state when the transfer torque of the engine clutch is the set torque or less.

A system and method for operating a vehicle equipped with an automatic stop and start system is disclosed. The vehicle includes an internal combustion engine, an automatic transmission and a fluid launch device with an impeller disconnect clutch. A controller may initiate an automatic stop or start of the engine under certain operating conditions. During an engine start/stop event, the engine is automatically shut down and the impeller clutch of the fluid launch device may be disengaged to decouple the engine and transmission from the driveline to provide for improved fuel economy and reduced emissions.

A saddle-riding type vehicle includes an automatic clutch mechanism configured to be activated by an actuator which enables a push start to be executed, so that even when a charged capacity of a battery is reduced, an engine can be started. A control unit of the vehicle proceeds to a push start control mode when an engine stopped state detection portion detects a stopped state of an engine, a vehicle stopped state detection portion detects a stopped state of the saddle-riding type vehicle, and a gear selected state detection portion detects a state in which any one of gears of a transmission is selected. In the push start control mode, the control unit applies a clutch to start the engine when a vehicle speed detection portion detects a predetermined vehicle speed or faster, and a cutoff switch state detection portion detects a change in state of a cutoff switch.

A transmission includes a first hydraulic clutch, a second hydraulic clutch, a third hydraulic clutch, a pump and a controller. The first, second, and third hydraulic clutches are configured to established a parked-ready condition upon engagement of all three clutches. The pump is configured to generate hydraulic fluid pressure. The controller is programmed to, in response to a command to start an engine that powers the pump, engage the first and second clutches. The controller is further programmed to, in response to engagement of the first and second clutches and obtaining operating hydraulic fluid pressure, engage the third clutch.

A method of preventing a vehicle clutch from sticking includes a wear compensation actuation step of actuating a wear compensation device in conjunction with engagement actuation of a clutch actuator after an ignition is turned off when an actuation condition of the wear compensation device is satisfied, and a clutch control step of controlling a clutch position so that the clutch position returns to a disengaged state of the clutch actuator by reactuating the wear compensation device, when a clutch position based on an amount of variation in an actuation length of the actuation rod fails to return to the disengaged state of the clutch actuator during returning of the engaged clutch actuator.

A hybrid vehicle capable of selecting between a state where a clutch coupling an engine and a motor is engaged and the vehicle travels by drive power of the engine, and a state where the clutch is released and the vehicle travels with the engine stopped, wherein, if there is a request to restart the engine while the engine is rotating after control to release the clutch and stop the engine has been started, then upon the condition that the engine number of revolutions is equal to or greater than a predetermined threshold value, and in a state where the output torque of the motor is limited to a previously established torque or less, control to increase the transmission torque capacity of the clutch is implemented, whereupon the output torque of the motor is increased to a torque that cranks the engine.