A vehicle anomaly analysis apparatus for analyzing an anomaly having occurred in a shift control operation executed in an automatic transmission of a vehicle, by using a rotational speed changed in process of the shift control operation. The vehicle anomaly analysis apparatus specifies cause of the anomaly in the shift control operation, by applying an anomaly-cause specifying model that indicates a relationship between a manner of chronological change of a racing amount and the cause of the anomaly in the shift control operation, to the manner of the chronological change of the racing amount upon occurrence of the anomaly in the shift control operation. The racing amount is an amount of increase of the rotational speed in the process of the shift control operation, relative to a reference rotational speed that is based on a gear ratio and an output rotational speed of the automatic transmission.

A method and a system of learning a pressure applied to a brake of a countershaft may include determining, when a shift condition is satisfied, whether a shifting to be performed is a power off upshift; releasing a clutch mounted between a power source and the transmission when the shifting to be performed is the power off upshift; detecting a contact duration until a speed of an input shaft of the transmission is lowered by a predetermined speed by applying a target pressure stored in a memory to the brake of the countershaft when the release of the clutch is completed; comparing the contact duration with a predetermined duration; correcting, when the contact duration is greater than the predetermined duration, the target pressure according to a difference between the contact duration and the predetermined duration; and storing and updating the corrected target pressure in the memory to apply a subsequent power on upshift.

A belt-slippage diagnostic apparatus for a continuously-variable transmission that includes a primary pulley, a secondary pulley and a belt looped over the primary and secondary pulleys. The belt-slippage diagnostic apparatus includes a slippage determination portion configured to determine occurrence of slippage of the belt on at least one of the primary and secondary pulleys, when a first-order derivative of a gear ratio, which is a ratio of a rotational speed of the primary pulley to a rotational speed of the secondary pulley, is not smaller than a first threshold value and a second-order derivative of the gear ratio is not smaller than a second threshold value.

An apparatus for fixing a sticking damper clutch may include: a transmission controller configured to determine whether a damper clutch sticks, using engine controller information received from an engine controller and damper clutch status information of the damper clutch; and a hydraulic pressure controller configured to fix the sticking damper clutch according to the determination result of the transmission controller.

The invention relates to a hydraulic circuit (100, 200, 300) having a first, hydraulically actuable clutch (K1) which is closed in a rest state and a second, hydraulically actuable clutch (K2) which is closed in the rest state, wherein the hydraulic circuit (100, 200, 300) is configured in such a way that a hydraulic medium which is present in a main pressure line (HD) can be loaded with a working pressure by means of a pressure generating device (DE) and/or by means of a pressure accumulator (DS), and the hydraulic medium can be discharged for pressure dissipation via a main return line (HR) into the return reservoir (T), and wherein the hydraulic circuit (100, 200, 300) has a first distributor pressure line (VD1) and a separate, first collector return line (SR1) for the hydraulic supply of a first part circuit (TK1) and at least one separate, second distributor pressure line (VD2) and at least one separate, second collector return line (SR2) for the hydraulic supply of a second part circuit (TK2), wherein the first clutch (K1) is assigned to the first part circuit (TK1) and the second clutch (K2) is assigned to the second part circuit (TK2), and wherein, in an operating state of the hydraulic circuit (100, 200, 300), either the first collector return line (SR1) or the second collector return line (SR2) is connected hydraulically to the main pressure line (HD).

An abnormality determination device of a lock up clutch includes a controller and a determining unit. The controller sets a lock up clutch in a torque converter at an engaged state or a disengaged state. The torque converter is provided in an automatic transmission of a vehicle. The determining unit determines, on the condition that deceleration of the vehicle on travel with the lock up clutch in the engaged state causes a control signal for disengagement to be outputted from the controller, the presence or the absence of the abnormality in the lock up clutch, on the basis of a determination result as to whether or not a difference between the number of engine rotations and the number of turbine rotations is equal to or larger than a first threshold that varies with a rate of deceleration of the vehicle.

Provided is a control device for a vehicle. A control device for a vehicle includes a vehicle that includes an engine and a main motor, and a transmission equipped with first and second input shafts which are respectively connected to the engine via first and second clutches, an output shaft through which power is output to drive wheels, first and second transmission mechanisms which respectively includes a plurality of transmission gears selectively joined to the first and second input shaft respectively, and an ECU. When the main motor is driven and when the engine is stopped, the ECU determines that the vehicle travels using power of the engine using the transmission gears of one of transmission mechanisms in a case where defective engagement release occurs such that a transmission gear of the other transmission mechanism is not disengaged.

A method and system for controlling clutch friction elements of an automatic transmission is provided. The method includes retrieving information about shift clutches from a data storage unit and acquiring information required to predict a temperature of a friction element for each shift clutch, deriving a predicted temperature value of a friction element for each shift clutch by using the information about the shift clutches and the information required to predict the temperature of the friction element, predicting whether or not overheating occurs for each shift clutch by comparing the derived predicted temperature value of the friction element for each shift clutch with an allowable temperature set for each shift clutch, and determining a target shift stage while avoiding the overheating clutch with a predicted temperature value exceeding the allowable temperature, through switching to an avoidance shift mode.

Provided is an automatic transmission capable of smoothly switching a switching mechanism. A control part ECU of a transmission recognizes an input torque and a friction torque when an instruction to switch a two-way clutch from a fixed state to a reverse rotation prevention state is received while a first clutch, a second clutch and a third clutch are in an open state, and switches the two-way clutch from the fixed state to the reverse rotation prevention state when the input torque is equal to or greater than the friction torque.

A control apparatus for a vehicle drive-force transmitting apparatus which defines a first drive-force transmitting path provided with a first clutch and a two-way clutch and a second drive-force transmitting path provided with a continuously variable transmission and a second clutch. The control apparatus switches the two-way clutch from its lock mode to its one-way mode, when the second drive-force transmitting path is to be established in place of the first drive-force transmitting path. The drive-force transmitting apparatus includes a hydraulic actuator configured to control switching of the two-way clutch between the lock mode and the one-way mode. When a request for establishing the second drive-force transmitting path in place of the first drive-force transmitting path is made during forward running of the vehicle with the two-way clutch being in the lock mode, the control apparatus executes a dither control for fluctuating a hydraulic pressure applied to the hydraulic actuator.