A method for operating a hybrid drive assembly for a motor vehicle, which has an internal combustion engine and an electric engine. A separating clutch arranged in drive terms between the internal combustion engine and the electric engine is set to a target clutch torque by at least partially engaging during an attempt to start the internal combustion engine. An actual clutch torque actually transmitted via the separating clutch and a speed of the internal combustion engine are determined during the attempt to start, and if a characteristic value dependent on the actual clutch torque exceeds a threshold value and if an integral of the speed over time continuously falls below a limit value during the attempt to start, the attempt to start is aborted.

A hybrid vehicle control apparatus including a torque converter temperature detector detecting a torque converter temperature, a rotor temperature detector detecting a rotor temperature, a stator temperature detector detecting a stator temperature, and an electronic control unit including a microprocessor. The microprocessor is configured to perform controlling an engine, a transmission, a lockup clutch, a motor-generator and a stator cooling device based on the torque converter temperature detected by the torque converter temperature detector, the rotor temperature detected by the rotor temperature detector and the stator temperature detected by the stator temperature detector so that the torque converter temperature is equal to or lower than a first predetermined temperature, the rotor temperature is equal to or lower than a second predetermined temperature and the stator temperature is equal to or lower than a third predetermined temperature.

A hybrid vehicle includes an engine, an electric machine, a disconnect clutch configured to selectively couple the engine to the electric machine, and a controller. The controller is programmed to, in response to a request to start the engine with the electric machine, command a target pressure to the disconnect clutch that depends on a seal friction derived from a measured line pressure of the disconnect clutch and a rate change of the measured line pressure.

The controller is programmed to perform first control that controls a driving force distributor such as to decrease a distribution rate upon satisfaction of a predetermined condition that a frequency of at least one rotation fluctuation of an output member of the drive system, a main drive wheel and a sub drive wheel is within a predetermined area, compared with the distribution rate upon non-satisfaction of the predetermined condition.

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.

A system and method for controlling a torque transfer clutch of a vehicle. A first data source indicates if the clutch is in AWD or 4×4 mode. An integrator system monitors energy transferred across the clutch. A temperature data source measures or calculates the clutch temperature. In a first case, the integrator accumulates data of the energy across the clutch during a monitoring period that is compared to a maximum accumulated energy value and initiates a powertrain torque dependent transfer point learn routine. In a second case, the controller responds to energy accumulator cycle data in a single monitoring cycle that is compared to a maximum cycle data value. In a third case, the controller responds to clutch temperature data and compares the temperature data to a maximum temperature value. The second and third cases initiate a non-powertrain torque dependent transfer point learn routine.

A vehicle control device for controlling a vehicle with a frictional engagement element provided between a drive source and drive wheels includes a first determination unit configured to determine whether or not a signal of an inhibitor switch indicates a traveling position, a second determination unit configured to determine whether or not an oil path communicating with the frictional engagement element is in a drain state, a temperature estimation unit configured to estimate temperature of the frictional engagement element, and a temperature estimation prohibition unit configured to prohibit temperature estimation of the frictional engagement element by the temperature estimation unit when the signal of the inhibitor switch indicates the traveling position and the oil path is in the drain state.

A vehicle control system for preventing malfunction of the clutch for selectively connecting the engine with the power train. The vehicle control system is applied to a vehicle having an engine, a motor disposed on a power train, and a clutch interposed therebetween. In order to prevent a malfunction of the clutch, the vehicle control system is configured to engage the clutch while causing a slip but without starting the engine if the engine has not yet been started.

A vehicle control unit performs filling control in which the vehicle control unit boosts an oil pressure in a second oil passage by supplying electric power to a pressure regulating valve with a switch valve being in a first state in which the switch valve connects a first oil passage to a clutch and disconnects the second oil passage from the clutch, torque replacement control in which the vehicle control unit increases motor torque while reducing shaft torque of an engine, and clutch disengagement control in which the vehicle control unit disengages the clutch while performing hydraulic control by the pressure regulating valve with the switch valve being in the second state in which the switch valve connects the second oil passage to the clutch and disconnects the first oil passage from the clutch.

A startup control device includes a vehicle temperature sensor configured to sense a temperature of the vehicle, a vehicle startup controller configured to select the second vehicle startup mode in a low temperature state in which the temperature of the vehicle is equal to or smaller than at least a first temperature judgment value when the request of the startup of the vehicle is sensed, and to select the third vehicle startup mode in an extremely low temperature state in which the temperature of the vehicle is equal to or smaller than a second vehicle temperature judgment value which is smaller than the first temperature judgment value when the request of the startup of the vehicle is sensed.