An all-wheel-drive vehicle includes a primary drive axle, a secondary drive axle, and an all-wheel-drive powertrain configured to selectively power the primary and secondary axles. The powertrain includes a powerplant and a clutch that couples the powerplant to the secondary axle when engaged and that decouples the powerplant from the secondary axle when disengaged. A controller is programmed to disengage the clutch to disable all-wheel drive and propel the vehicle solely with the primary drive axle based on repeated occurrence of power output of the powertrain being less than a value.

Provided is a lockup control device and a lockup control method for a vehicle power transmission device provided with a fluid transmission device including a lockup clutch. The lockup clutch is controlled to perform slip-engagement such that a differential rotation between an input-side rotating member and an output-side rotating member of the fluid transmission device is a target differential rotation set in advance, and the target differential rotation is corrected based on transition of a heat accumulation amount applied to friction members of the lockup clutch.

There are included a transmission mechanism that includes an input member driven by an engine and an output member drive-coupled to wheels and that can change a gear ratio between the input member and the output member; a clutch SSC that is interposed between an output shaft of the engine and the input member and can connect and disconnect power transmission between the output shaft of the engine and the input member of the transmission mechanism; and a control part that controls engagement and disengagement of the clutch SSC by electrical instructions. When the control part determines that a drag state of the clutch SSC has occurred (t2) when the control part outputs an electrical instruction to bring the clutch SSC into a disengaged state, the control part outputs an electrical instruction to bring the clutch SSC into a completely engaged state (t3 to t4).

Provided is a lockup control device and a lockup control method for a vehicle power transmission device provided with a fluid transmission device including a lockup clutch. The lockup clutch is controlled to perform slip-engagement such that a differential rotation between an input-side rotating member and an output-side rotating member of the fluid transmission device is a target differential rotation set in advance, and the target differential rotation is corrected based on transition of a heat accumulation amount applied to friction members of the lockup clutch.

Methods and systems for operating a driveline that includes a dual clutch transmission are described. In one example, clutches of the dual clutch transmission may be cooled via activating and adjusting a flow rate of an electric pump. Further, driveline operating modes may be entered or exited in response to clutch operating conditions so that driveline robustness may be enhanced.

A control apparatus of an automatic transmission including a plurality of planetary gear mechanisms and engaging mechanisms configured to establish a gear range by switching inputs/outputs of the plurality of planetary gear mechanisms, comprises an oil pressure supply device which supplies an oil pressure to operate the engaging mechanisms between an engaging state and a release state in which the engaging state is canceled; and a gear change controller which controls an operation state of each of the engaging mechanisms of the planetary gear mechanisms to establish one gear range of a plurality of gear ranges. The gear change controller executes gear change control of restricting the gear change to the gear range in a case in which the temperature of each of the engaging mechanisms in the gear range after the gear change is predicted to be not less than an allowable temperature.

A method is provided for balancing clutch wear in a dual clutch transmission. The method involves performing the steps of determining which clutch unit of first and second clutch units is subjected to the most accumulated wear and selecting a gear actuated by the other clutch unit during launch of the vehicle.

When an input torque becomes greater by a predetermined value or more due to an operation of increasing an amount of accelerator depression amount or the like during a gear shift, a controller for an automatic transmission updates a target gear shift characteristic value to a target gear shift characteristic value which is set when the gear shift is started with the input torque based on the input torque at the updating time, and performs gear shift control from a degree of progress in gear shift at the updating time based on the updated target gear shift characteristic value. Since the target gear shift characteristic value can be changed with respect to an increase in the input torque during the gear shift by this control, it is possible to prevent a decrease in durability of frictional engagement elements.

When an engagement-side clutch taking charge of rotation control in an upshift is the same as a rotation control clutch of a previous gear shift, it is determined that there is a likelihood that a thermal load of a clutch friction material will increase, and the thermal load of the clutch friction material is decreased by delaying gear shift start. By setting a delay time by which the gear shift start is delayed when an accelerator depression amount is small to be shorter than when the accelerator depression amount is large depending on the accelerator depression amount, a gear shift which is an upshift can be performed without unnecessary waiting.

A control apparatus of an automatic transmission including a plurality of planetary gear mechanisms and engaging mechanisms configured to establish a gear range by switching inputs/outputs of the plurality of planetary gear mechanisms, comprises an oil pressure supply device which supplies an oil pressure to operate the engaging mechanisms between an engaging state and a release state in which the engaging state is canceled; and a gear change controller which controls an operation state of each of the engaging mechanisms of the planetary gear mechanisms to establish one gear range of a plurality of gear ranges. The gear change controller executes gear change control of restricting the gear change to the gear range in a case in which the temperature of each of the engaging mechanisms in the gear range after the gear change is predicted to be not less than an allowable temperature.