The invention relates to the actuation of a converter lock-up clutch (44) of a hydrodynamic torque converter (4) in a vehicle drive-train by means of a safety function where, in addition to a driving strategy function, the safety function can actuate the converter lock-up clutch (44) by issuing a clutch actuation command. For this purpose, at least one rotation speed at the torque converter (4) is monitored. If the monitored rotation speed is below a rotation speed threshold, the safety function commands an actuation of the converter lock-up clutch (44) in its opening direction.

A method for controlling a vehicle including a continuously variable transmission includes determining, by a controller, whether a speed difference between a speed of a vehicle according to revolutions per minute (RPM) of a driving wheel of the vehicle and a speed of the vehicle according to revolutions per minute (RPM) of a towed wheel of the vehicle is equal to or greater than a speed reference value and reducing, by the controller, torque of an engine providing a driving force to a driving pulley of the continuously variable transmission when the difference in vehicle speed is equal to or greater than the speed reference value.

A method for controlling a vehicle including a continuously variable transmission includes determining, by a controller, whether a speed difference between a speed of a vehicle according to revolutions per minute (RPM) of a driving wheel of the vehicle and a speed of the vehicle according to revolutions per minute (RPM) of a towed wheel of the vehicle is equal to or greater than a speed reference value and reducing, by the controller, torque of an engine providing a driving force to a driving pulley of the continuously variable transmission when the difference in vehicle speed is equal to or greater than the speed reference value.

A hydraulic control system for a multiple speed motor vehicle automatic transmission having electronic transmission range selection (ETRS) provides both a forward gear ratio and Park options during default conditions where the transmission loses electronic control when the ETRS system is in a drive mode. The hydraulic control system includes a two position default disable solenoid valve, an ETRS valve, a park servo, position sensors, a default disable valve, a drive select valve, various orifices and blow-off valves as well as main and auxiliary pumps, a torque converter, a torque converter regulator and control valve and a plurality of linear force solenoid valves and clutch regulation valves which control a like plurality of clutch and brake actuators.

A hydraulic control system for a multiple speed motor vehicle automatic transmission having electronic transmission range selection (ETRS) provides both a forward gear ratio and Park options during default conditions where the transmission loses electronic control when the ETRS system is in a drive mode. The hydraulic control system includes a two position default disable solenoid valve, an ETRS valve, a park servo, position sensors, a default disable valve, a drive select valve, various orifices and blow-off valves as well as main and auxiliary pumps, a torque converter, a torque converter regulator and control valve and a plurality of linear force solenoid valves and clutch regulation valves which control a like plurality of clutch and brake actuators.

Presented are clutch-type engine disconnect devices, methods for making/using such disconnect devices, and motor vehicles equipped with such disconnect devices. An engine disconnect device includes a notch plate, which has multiple notches and attaches to a torque converter, and a pocket plate, which has multiple pockets and attaches to an engine's crankshaft. A pawl is movably mounted within each notch; these pawls selectively engage the notches with the pockets. A notch plate insert is nested within each notch, supporting thereon one of the pawls. A selector plate interposed between the pocket and notch plates moves from a first position, to shift the pawls out of engagement with the pockets, and a second position, to move the notch plate inserts within the notches and allow the pawls to engage the notches with the pockets to thereby lock the notch plate to the pocket plate to rotate in unison with each other.

A control apparatus for a vehicle provided with (i) a power source, (ii) drive wheels and (iii) a fluid transmission device disposed between the power source and the drive wheels and including a lockup clutch to which a fluid pressure is supplied. A feedback control is executed for correcting a command value of the fluid pressure by a correction amount such that an actual value of a slip amount of the lockup clutch becomes substantially equal to the target value of the slip amount in a slip control. When the actual value has been converged into a given range with respect to the target value, the correction amount is obtained, and the command value for a next execution of the slip control is corrected by learning with use of the obtained correction amount. The given range is set depending on the target value of the slip amount.

A method for calibrating an actuation of a converter lock-up clutch of a hydrodynamic torque converter having a pump wheel and a turbine wheel connected to a power-split transmission. The transmission has at least two clutches each connected to a respective power-split shaft assembly and each configured be actuated separately to close and open in order to apply a clutch torque to the turbine wheel so that a rotation speed difference between the pump wheel and the turbine wheel changes. The method includes opening the converter lock-up clutch and the at least two clutches each connected to a respective power-split shaft assembly of the transmission, rotating the pump wheel with a specified rotation speed, and applying a clutch torque to the turbine wheel as a function of an actual rotation speed difference. Clutches connected to a different respective power-split shaft assembly of the transmission are actuated in the closing direction.

A power transmission device includes a torque converter device, a first hydraulic pump, a first oil channel, a second oil channel, a third oil channel, a second pressure control valve, and a controller. The torque converter device has a torque converter and a lock-up clutch. The first oil channel supplies hydraulic fluid from the first hydraulic pump to the torque converter. The second oil channel drains hydraulic fluid from the torque converter. The third oil channel communicates with the first oil channel and the second oil channel. The second pressure control valve is disposed in the third oil channel. The controller sets the second pressure control valve to an open state when the lock-up clutch is in an engaged state.

A method for operating a hybrid vehicle includes, determining a shift element to be utilized for decoupling of slip and a decoupling differential speed depending on whether a starting process is carried out, depending on whether the transmission is transferred from a torque-transmitting state into a non-torque-transmitting state or from a non-torque-transmitting state into a torque-transmitting state, depending on whether a gear ratio change is carried out, and depending on whether the hybrid vehicle includes a hydrodynamic starting component.