A method for determining a conveying capacity of a hydraulic pump includes opening a blockable flow cross-section in order to connect a pressure side of the hydraulic pump to an area of the hydraulic system through the flow cross-section after operating the hydraulic pump driven at a defined rotational speed. The flow cross-section is configured with the hydraulic pump such that an entire conveying volume flow provided by the hydraulic pump is guided through the flow cross-section when the flow cross-section is open. The method further includes comparing a change to an operating state of the transmission resulting from opening of the flow cross-section to a reference change to the operating state and determining the conveying capacity of the hydraulic pump as a function of a deviation between the change to the operating state and the reference change to the operating state.

A method of adjusting and using operating parameters of a transmission of a vehicle may include accessing a stored list of clutch parameters, performing a dynamic condition procedure while the vehicle is driven to revise minimum on-coming apply pressure for each friction element based on a sensed performance of an element within the vehicle powertrain, storing the modified minimum on-coming apply pressures, and operating the vehicle. A related transmission control device operates a transmission using parameters obtained during a dynamic condition procedure.

An automatic transmission for a vehicle drivetrain includes a transmission housing, an input shaft, an output shaft, and a plurality of gears within the transmission housing. The plurality of gears defines multiple mechanical gear ratios between the input shaft and the output shaft. The transmission further includes a plurality of clutches operable to selectively engage the multiple mechanical gear ratios, and a plurality of rotational speed sensors. Each rotational speed sensor is operable to measure rotational speeds relative to the transmission housing for of one of the input shaft, the output shaft, or one of the plurality of gears. The transmission further includes a transmission control system configured to receive signals representing the measured rotational speeds from the plurality of rotational speed sensors and control the plurality of clutches to change between gear ratios based at least in part on the signals representing the measured rotational speeds.

Methods and systems are provided for operating a powertrain or driveline of a hybrid vehicle that includes two electric machines and a transmission are described. In one example, vehicle propulsion is maintained while transmission operating parameters are determined for improving transmission operation. In particular, a rear drive unit maintains vehicle speed and monitors torque delivered via an output of the transmission.

A control apparatus includes an ECU that is configured to: start engagement transition control for outputting an engagement transitional hydraulic pressure command value that causes an engagement device to be actuated from a released state toward an engaged state from when an operating member is displaced from a non-drive operating position; when an engagement transition time is longer than a target time, learn the engagement transitional hydraulic pressure command value such that the engagement transitional hydraulic pressure command value increases; when the engagement transition time is shorter than the target time, learn the engagement transitional hydraulic pressure command value such that the engagement transitional hydraulic pressure command value reduces; and prohibit learning of the engagement transitional hydraulic pressure command value or invalidate the learned engagement transitional hydraulic pressure command value, when the operating time of the operating member is longer than a predetermined time.

When an inertia phase has started while torque phase control is being executed, the torque phase control is ended, a target torque capacity of an engaging element in inertia phase control is corrected on the basis of a difference between the target torque capacity of the engaging element at the time when the inertia phase has started and the target torque capacity of the engaging element at the time when the torque phase control has completed (or a difference between the target torque capacity of the engaging element at the time when the inertia phase has started and the target torque capacity of the engaging element, which is set at the time when the inertia phase control has started), and the inertia phase control is started.

A clutch-to-clutch transmission monitoring system for an automobile vehicle includes a control software generating a control signal. A monitor is in communication with the control software. A pre-compute monitor is in communication with the control software. The pre-compute monitor also receives the input data and outputs an operating threshold signal to the control software. The operating threshold signal defines allowed operating bounds for at least one component in communication with the monitor. A post-compute monitor is in communication with both the control software and the pre-compute monitor. The post-compute monitor receives both the control signal and the operating threshold signal. The post-compute monitor compares the control signal to the operating threshold signal to identify if the control signal violates the allowed operating bounds defined by the pre-compute monitor.

A method of adjusting operating parameters of a transmission of a vehicle may include accessing a stored list of clutch parameters; performing a static condition procedure to revise the clutch parameters; and performing a dynamic condition procedure to further revise the clutch parameters. The method may be performed by a transmission control device for the vehicle, the vehicle having a powertrain including an engine, the transmission with a plurality of solenoid actuated friction elements, and sensors. The static condition procedure and dynamic procedures may be performed incrementally, and the static condition procedure may be performed more than once to fine tune the results.

A control device for a vehicle is provided. The control device includes an automatic transmission constituted of a stepwise variable transmission mechanism configured to switch a plurality of shift stages by engagement and disengagement of a plurality of friction engaging elements, an engine as a driving source, a motor configured to assist a driving force of the engine, a hydraulic controller configured to supply a hydraulic pressure to control the engagement and the disengagement of the friction engaging element, and a control unit configured to control the automatic transmission to a target speed ratio through changing the shift stage of the stepwise variable transmission mechanism. The control unit performs a learning control that learns at least one of hydraulic pressure of the engagement and the disengagement of the friction engaging element, and inhibits the assist of the driving force to the engine by the motor in performing the learning control.

A continuously variable transmission, a control system, and a method are provided. The control system and method are configured to learn a desired running pressure to be applied to a clutch that is lower than a pulley clamping pressure and higher than a pressure at which the clutch would slip (a clutch critical pressure), so that the clutch can act as a fuse to avoid pulley slip. A plurality of clutch slip tests are performed, each of which include decreasing pressure supplied to the clutch until a clutch slip occurs. Clutch slip data points are collected at the point of slip and used to determine a gain and an offset, where the gain is a clutch pressure versus clutch torque capacity gain, and the offset is a clutch pressure offset, which is used to determine the clutch critical pressure.