Abstract: A transmission and control method are disclosed which ensure proper stroke pressure and minimize torque transients during a shift event. The transmission includes a clutch having a torque capacity based on a fluid pressure, a torque sensor adapted to measure a torque value that varies in relationship to the torque capacity, and a controller. The method includes varying the fluid pressure around a predetermined value, measuring a resulting torque difference with the torque sensor, and adjusting a clutch control parameter if the resulting torque difference is less than a threshold value.

Abstract: A transmission and control method are disclosed which ensure proper stroke pressure and minimize torque transients during a shift event. The transmission includes a clutch having a torque capacity based on a fluid pressure, a torque sensor adapted to measure a torque value that varies in relationship to the torque capacity, and a controller. The method includes varying the fluid pressure around a predetermined value, measuring a resulting torque difference with the torque sensor, and adjusting a clutch control parameter if the resulting torque difference is less than a threshold value.

Abstract: A modular electronic control system for a geared multiple-ratio transmission wherein pressure profiles for each ratio shift actuator are used to provide seamless transitions during both positive and negative engine torque conditions to improve shift feel and responsiveness to ratio change commands. The system provides shift staging for sequenced shifts between ratios as well as for so-called “change-of-mind” shifts in which a sequence shift is interrupted as a new destination gear is introduced. A constant ratio change occurs during sequenced shifts. A change-of-mind shift can be performed directly where the new destination gear is commanded immediately. Independent pressure profiles for each clutch involved in a commanded shift are used to accommodate various types of shifts.

Abstract: A method for cleaning a solenoid-operated regulator valve wherein command current applied to a solenoid actuator establishes a defined response of a valve. Cleaning current pulses applied to the solenoid establish a response that does not interfere with the effectiveness of the valve function. The pulse width, pulse amplitude, pulse direction and pulse period are determined by the degree of contamination of the valve environment.

Abstract: A method and system for detecting degraded operation of a solenoid. A current through the solenoid is sampled at predetermined time intervals within a predetermined time period. A maximum value of the sampled current is first detected. Next, a minimum value of the sampled current subsequent to the maximum value is detected. Finally, a predetermined increase in the sampled current from the minimum value is detected to verify operation of the solenoid.