A hydraulic pressure control device of a vehicle driving device, the hydraulic pressure control device includes a range switcher having a first signal solenoid valve capable of supplying a first signal pressure and a spool switchable between a first position reached via the first signal pressure and a second position reached via a biasing force of a biasing member.

A hydraulic control system for a motor vehicle transmission includes a pressure regulation subsystem in fluid communication with a pump for providing pressurized hydraulic fluid. A manual valve assembly is in direct fluid communication with the pressure regulation subsystem, and is moveable by an operator of the motor vehicle between at least park, neutral, drive, and reverse positions. A default disable valve assembly is in direct fluid communication with the manual valve assembly, a default disable solenoid, and a default select valve assembly. The manual valve assembly is in direct fluid communication with the default disable valve assembly which is in direct fluid communication with the default disable solenoid and the default select valve assembly. The default disable solenoid enables the default disable valve assembly to enable three default modes of operation and the default select valve assembly selects between two of the three default modes of operation.

The present invention provides a control unit. When the control unit performs shifting from a state in which a first shift speed is established by supplying engagement pressures to both hydraulic oil chambers and engaging a predetermined engagement element to a second shift speed by switching engagement and disengagement states of engagement elements other than the predetermined engagement element (Step S1), the control unit reduces the supply of the engagement pressure to one of the two hydraulic oil chambers to a level lower than that in the state in which the first shift speed is established (Step S3).

A method for controlling a line pressure of a hybrid vehicle includes applying, by a controller, a set current corresponding to a target pressure to a first solenoid valve controlling the line pressure, driving, by the controller, a second solenoid valve to open an engine clutch after the applying step, comparing, by the controller, a difference value between a real pressure of the engine clutch sensed by a pressure sensor and the target pressure with a preset pressure after the driving step, and as a result of performing the comparing step, if the difference value is equal to or greater than the preset pressure, controlling, by the controller, an increase of a revolution per minute (RPM) speed of the electric oil pump and an increase of a pressure of the first solenoid valve to be alternately generated.

An actuator diagnostic apparatus is provided for an electronic control unit of a vehicle. The actuator diagnostic apparatus of the electronic control unit for a vehicle is characterized by containing: a high-side driver which drives an actuator from a high-side; an output voltage sensing unit which senses an output voltage of the high-side driver; a low-side driver which drives the actuator from a low-side; a pull-down switch which pulls down an input voltage of the high-side driver; a shutdown driver which actuates the pull-down switch; and a diagnostic control unit which diagnoses shutdown of the actuator upon receiving an input of the output voltage from the output voltage sensing unit after respectively actuating the high-side driver, the low-side driver, and the shutdown driver in accordance with a shutdown diagnosis order.

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 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.

Non-inverted park lock systems and methods include an engine controller configured to control an engine of a vehicle in communication with a separate transmission controller via a controller area network (CAN), wherein the transmission controller is configured to control a transmission of the vehicle; and a conductor connecting the engine controller to a park lock solenoid disposed in the transmission and configured to move a park pawl to engage/disengage park. The engine controller keeps the park pawl disengaged from park during a power loss malfunction at the transmission controller and the transmission controller keeps the park pawl disengaged from park during a power loss malfunction at the engine controller by maintaining hydraulic pressure in the transmission at a threshold level until park is requested via the shifter.

A valve system for a hydraulic emergency driving gear function of a hydraulic control unit for a motor vehicle automatic transmission includes a position valve (104) with a first piston slide (120) and an electromagnetic pressure regulator (86) having a decreasing characteristic curve. The first piston slide (120) is preloaded in a first position. When the first piston slide (120) is in a second position, the electromagnetic pressure regulator (86) is configured for connecting a system pressure-carrying line (18) of the motor vehicle automatic transmission to a first emergency driving gear clutch (12) of the motor vehicle automatic transmission and to a second emergency driving gear clutch (15) of the motor vehicle automatic transmission, whereby the first emergency driving gear clutch (12) and the second emergency driving gear clutch (15) are actuated, so that an emergency driving gear of the motor vehicle automatic transmission is engaged.

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.