A limited slip differential (LSD) is mounted on a driven axle of a vehicle to drive left and right wheels. To control the LSD, a speed of the vehicle is determined. A value of a preload for application to the LSD is also determined. The value of the preload is based on a predicted engine torque and on the speed of the vehicle. A preload is applied to the LSD when the value of the preload is greater than zero.

The disclosure provides a control method, a control device for vehicular automatic transmission, and a recording medium. The control device includes an ON/OFF control solenoid controlling LC to either ON or OFF, and an LC pressure control linear solenoid controlling LC pressure between a released state and a fully engaged state. The control device acquires, when an accelerator pedal opening of a vehicle is on a deceleration side in a fully closed state, a torque converter slip ratio when the ON/OFF control solenoid maintains ON for a predetermined time period and the LC pressure control linear solenoid is controlled such that the LC pressure is OFF, and determines whether or not the second solenoid has a high-pressure fixation failure according to whether or not the slip ratio is within a predetermined range from a slip reference value.

The disclosure provides a control method, a control device for vehicular automatic transmission, and a recording medium. The control device includes an ON/OFF control solenoid controlling LC to either ON or OFF, and an LC pressure control linear solenoid controlling LC pressure between a released state and a fully engaged state. The control device acquires, when an accelerator pedal opening of a vehicle is on a deceleration side in a fully closed state, a torque converter slip ratio when the ON/OFF control solenoid maintains ON for a predetermined time period and the LC pressure control linear solenoid is controlled such that the LC pressure is OFF, and determines whether or not the second solenoid has a high-pressure fixation failure according to whether or not the slip ratio is within a predetermined range from a slip reference value.

A wheel loader includes a boom, a forward clutch, and a controller configured to control hydraulic pressure of hydraulic oil supplied to the forward clutch. The controller performs clutch hydraulic pressure control for bringing the forward clutch into a semi-engagement state by controlling the hydraulic pressure of the hydraulic oil supplied to the forward clutch on condition that the wheel loader advances while raising the boom in at least a loaded state.

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.

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.

A control device of a gear transmission-equipped vehicle includes a power controller that starts power reduction control when it is determined that a start condition is satisfied, the power reduction control being control of reducing power transmitted from a driving source to a gear transmission. The start condition includes: a condition that a detection value of a gear position sensor that detects a current gear position of the gear transmission falls within a transition region between engagement regions corresponding to respective gear positions; and a condition that a speed difference obtained by subtracting a rotational speed of an output shaft of the gear transmission from a rotational speed of an input shaft of the gear transmission is a threshold or more.

A continuously variable transmission (2) has a torque convertor (3) having a lock-up clutch (30) and a continuously variable transmission mechanism (5). A control unit (10) has a shift control unit (10C) configured to be able to perform a pseudo stepwise up-shift control that varies a transmission ratio of the continuously variable transmission mechanism (5) stepwise, a lock-up control unit (10A) configured to control an engagement state of the lock-up clutch (30), and a torque control command unit (10D) configured to perform a torque-down control of a driving source (1). When the engagement control of the lock-up clutch (30) and the pseudo stepwise up-shift control are performed at the same time, the torque control command unit (10D) configured to perform the torque-down control with a greater torque reduction amount.

A continuously variable transmission (2) has a torque convertor (3) having a lock-up clutch (30) and a continuously variable transmission mechanism (5). A control unit (10) has a shift control unit (10C) configured to be able to perform a pseudo stepwise up-shift control that varies a transmission ratio of the continuously variable transmission mechanism (5) stepwise, a lock-up control unit (10A) configured to control an engagement state of the lock-up clutch (30), and a torque control command unit (10D) configured to perform a torque-down control of a driving source (1). When the engagement control of the lock-up clutch (30) and the pseudo stepwise up-shift control are performed at the same time, the torque control command unit (10D) configured to perform the torque-down control with a greater torque reduction amount.

A control device performs upshifting in a state in which an operating point of a rotating electrical machine for outputting requirement-based torque at wheel-based rotational speed falls within an operable range of the rotating electrical machine both before and after shifting a shift speed by the upshifting, and in which before shifting the shift speed, output torque from the rotating electrical machine is less than or equal to determination torque (T1), the wheel-based rotational speed being rotational speed of the rotating electrical machine based on rotational speed (V) of a wheel, the requirement-based torque being output torque from the rotating electrical machine based on required wheel transmission torque, and the determination torque (T1) being torque obtained by subtracting an amount of increased torque (ΔTmg) resulting from torque increase control from maximum torque (Tmax) that can be outputted from the rotating electrical machine at the wheel-based rotational speed.