This invention provides two methods for detecting mechanical or electrical faults in a solenoid valve. In the first method, a force sensor is placed in the valve in such a way as to detect changes in the impact force of the plunger against the solenoid valve body or coil housing (depending upon the direction of movement of the plunger upon application of the electric current/magnetic field). A second method is provided which makes use of an accelerometer placed in such a way as to detect changes in the response of the plunger to the application of the magnetic field.

Provided is an automotive transmission control device in which a shift range signal can be generated as accurately as possible and control of vehicle travel can be maintained even when a signal input port for a computation device develops a fault. The automotive transmission control device according to the present invention: is provided with three input ports for receiving shift range signals; and provisionally determines the shift range state by the majority decision of the input ports, estimates the shift range state on the basis of the travel state of the vehicle, and performs a final determination of the shift range state by using both the provisional determination and the estimation.

A control device provided in a gear shifting device includes an electronic control unit. The electronic control unit determines whether an abnormality of the gear shifting device has occurred, performs a fail-safe process of switching the frictional engagement element corresponding to an abnormality to a disengaged state and fixing the gear shift ratio of the gear shifting device when it is determined that an abnormality has occurred, determines whether the abnormality has been relieved based on a behavior of an input signal at the time of operating a drive device of the frictional engagement element corresponding to an abnormality on condition that the frictional engagement element is maintained in the disengaged state after it is determined that the abnormality has occurred, and releases the fail-safe process when it is determined that the abnormality has been relieved.

A fault evaluation device for an automatic transmission evaluates a fault of the automatic transmission. The fault evaluation device is used for a vehicle having the automatic transmission and a control device configured to execute a learning process for correcting a target pressure for oil to be supplied to the automatic transmission such that variations in acceleration of the vehicle during shifting of the automatic transmission are small. The fault evaluation device includes a processor and a memory. The memory stores mapping data that prescribe mapping. The processor is configured to output an output variable, which is an evaluation value that indicates the presence or absence of the fault of the automatic transmission, when an input variable is input.

An abnormality cause determining device that is applied to a vehicle including an electromagnetic actuator includes a storage device and an execution device. The storage device is configured to store map data which is data for defining a map. The map includes a current variable which is a variable indicating a current flowing actually in the electromagnetic actuator as an input variable and includes a cause variable which is a variable indicating a cause of an abnormality of an onboard unit including the electromagnetic actuator as an output variable. The execution device is configured to perform an acquisition process of acquiring a value of the input variable based on a detection value from a sensor which is mounted in the vehicle and a calculation process of calculating a value of the output variable by inputting the value of the input variable to the map.

A control device provided in a gear shifting device includes an electronic control unit. The electronic control unit determines whether an abnormality of the gear shifting device has occurred, performs a fail-safe process of switching the frictional engagement element corresponding to an abnormality to a disengaged state and fixing the gear shift ratio of the gear shifting device when it is determined that an abnormality has occurred, determines whether the abnormality has been relieved based on a behavior of an input signal at the time of operating a drive device of the frictional engagement element corresponding to an abnormality on condition that the frictional engagement element is maintained in the disengaged state after it is determined that the abnormality has occurred, and releases the fail-safe process when it is determined that the abnormality has been relieved.

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.

A device for a vehicle including: a memory configured to store mapping data including machine learning data defining a mapping that uses an estimation variable that is a variable indicating a vehicle operation status of the vehicle and a detection value of a sensor detecting an oil temperature of a power transmission device as input variables, and uses an element corresponding to the input variables as an output variable; and a processor configured to: acquire the input variables; use the mapping to acquire the element as the output variable of the mapping corresponding to the input variables; and determine based on the element whether the detection value becomes equal to or higher than a threshold value due to occurrence of an abnormality in the power transmission device or a mode of vehicle operation by the driver of the vehicle.

A degradation estimation device includes a storage device and an execution device. The storage device is configured to store mapping data that defines a map that outputs an output variable indicating a degree of degradation of a seal member when an input variable is input. The map includes a thermal history variable and a load history variable as the input variable. The thermal history variable is a variable indicating a period during which the seal member has been exposed to a temperature within a predetermined temperature range. The load history variable is a variable indicating the number of times a load has acted on the seal member. The execution device is configured to perform an acquisition process of acquiring the input variable and a calculation process of outputting a value of the output variable by inputting the input variable acquired in the acquisition process to the map.

A method for calculating a degradation degree of a damper clutch of an automatic transmission of a vehicle includes: filtering, by a controller, a vibration signal of the vehicle according to driving of the vehicle in order to remove a vibration signal of the vehicle corresponding to a natural frequency of an engine of the vehicle from the vibration signal of the vehicle according to the driving of the vehicle; converting, by the controller, the filtered vibration signal into a signal including a sinusoidal wave having a natural frequency of the automatic transmission based on a gear stage of the automatic transmission of the vehicle by using a frequency analysis method; and calculating, by the controller, a degradation degree of the damper clutch included in a torque converter of the automatic transmission based on a magnitude of the sinusoidal wave having the natural frequency of the automatic transmission.