A transmission includes a gearing arrangement configured to shift speed ratios by disengaging an off-going shift element and engaging an oncoming shift element and an electrohydraulic valve having an actuatable valve element configured to control an engagement state of the oncoming shift element. A controller is programmed to, during a shift of the transmission, in response to the off-going shift element disengaging and an expected ratio change not initiating, monotonically increase current to the valve to a maximum value to overcome frictional resistance on the valve element, and programmed to, in response to expiration of a timer and the ratio change still not initiating, send a repeating pattern of high and low current signals according to a duty cycle to overcome frictional resistance of the valve element.

A sensor arrangement detects an angle of an actuator which is rotationally arranged on a support. The arrangement includes a first sensor element and a second sensor element. The first sensor element can be coupled to the actuator in order carry out a movement with respect to the support in accordance with a rotation of the actuator. The second sensor element can be rotationally fixed on the support and can be coupled to the first sensor element in order to produce, when rotating the actuator and a thus resulting movement between the first sensor element and the second sensor element, a sensor signal which is dependent on the rotation carried out by the actuator.

A transmission includes an input shaft coupled to a prime mover, a countershaft, main shaft, and an output shaft, with gears between the countershaft and the main shaft. A shift actuator selectively couples the input shaft to the main shaft by rotatably coupling gears between the countershaft and the main shaft. The shift actuator is mounted on an exterior wall of a housing including the countershaft and the main shaft. An integrated actuator housing includes a single external power access for the shift actuator. A controller interprets a shaft displacement angle, determines if the transmission is in an imminent zero or zero torque region, and performs a transmission operation in response to the transmission in the imminent zero or zero torque region.

A virtual manual transmission system for an electric vehicle for simulating the behavior of a vehicle having a manual transmission by controlling a motor while protecting an electric storage device. A controller is configured to: change torque of the motor when a virtual manual shifting is executed by operating a clutch device, an accelerator device, and a shifting device; and reduce a regulation on a change rate of the torque of the motor or an input/output power to/from the electric storage device.

A system includes a driveline, a user interface, and a control system. The driveline includes an engine, a transmission, and a clutch positioned to selectively couple the engine to the transmission. The user interface is configured to facilitate operator shifting of the transmission. The control system is configured to perform a transmission auto-shift procedure where the control system monitors engine speed of the engine for a period of time following completion of a downshift event with the transmission from a first, higher gear to a second, lower gear, compares the engine speed to at least one speed threshold, and automatically upshifts the transmission from the second, lower gear back to the first, higher gear (i) following expiration of the period of time and/or (ii) in response to the engine speed exceeding the at least one speed threshold during the period of time.

An automatic transmission that includes a speed change mechanism including a gear mechanism that can attain a plurality of shift speeds, and a plurality of friction engagement elements that are selectively engaged to attain each shift speed in the gear mechanism; a hydraulic control device that can regulate engagement pressures to be supplied to hydraulic servos of the plurality of friction engagement elements and that can supply lubricating oil that lubricates the speed change mechanism; and a control unit that sends a command about the engagement pressures to the hydraulic control device to control engagement states of the plurality of friction engagement elements.

Methods and systems for improving operation of a vehicle driveline that includes an engine and an automatic transmission with a torque converter are presented. In one non-limiting example, the engine may be stopped while a vehicle in which the engine operates is rolling. A transmission coupled to the engine may be shifted as the vehicle rolls so that vehicle response may be improved if a driver requests an increase of engine torque.

A system for controlling fluid flow to and from a clutch includes a motor, a pump, and a valve assembly. The valve assembly includes a housing defining an interior. The housing defines a first orifice operably coupled to the pump and a second orifice operably coupled to the clutch. The valve assembly also includes a piston operably coupled to the motor and disposed within the interior of said housing. The piston is movable between a first position for allowing the fluid flow between the first orifice and the second orifice, a second position for obstructing the fluid flow between the first orifice and the second orifice, and a third position for limiting the fluid flow between the first orifice and the second orifice. The valve assembly additionally includes a biasing member coupled to the piston. The biasing member biases the piston toward the first position.

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 shift by wire system is configured to systematically separate a shift dial and an autonomous driving dial, thereby preventing an erroneous manipulation of an autonomous driving mode and allowing effortless selection of the autonomous driving mode. The shift by wire system includes a shift dial shifting to engage a stop gear, a reverse gear, and a forward gear and an autonomous driving dial hidden by the shift dial in the stop gear or reverse gear and exposed from the shift dial in the forward gear to implement the autonomous driving mode.