Fca US LLC

Steven B Christ

William R Mayhew

Stephen Ronald Tokish

Quan Zheng

Niranjan Das

A method of draining transmission fluid through a drain hole of a transmission having an electrically driven auxiliary oil pump therein is provided. The method includes enabling, at a service computer, an oil drain service. The auxiliary oil pump is commanded on such that transmission fluid is pumped throughout the transmission and out of the drain hole. A determination is made whether the transmission fluid has sufficiently been drained out of the drain hole. The auxiliary oil pump is commanded off based on a determination that sufficient transmission fluid has been sufficiently drained out of the drain hole.

Transmission fluid change using internal pump

A hydraulic piston position determination system for a vehicle includes a hydraulic piston actuator configured to move a piston member in response to a hydraulic fluid pressure to engage/disengage a friction member, a hydraulic solenoid valve configured to control the hydraulic fluid pressure at the hydraulic piston actuator by regulating a flow of hydraulic fluid from a hydraulic fluid supply system, and a controller configured to control the hydraulic piston actuator by controlling the hydraulic solenoid valve according to an actual duty cycle based on a flow demand change associated with the hydraulic piston actuator, and determine a position of the hydraulic piston actuator based on (i) a magnetic reluctance change and (ii) a difference between the actual duty cycle and a steady-state duty cycle for the hydraulic solenoid valve.

Hydraulic motion detection via solenoid electronic feedback

A transmission control system and method involve receiving, by a controller and from a turbine shaft speed sensor, a rotational speed of a turbine shaft of an automatic transmission, receiving, by the controller and from an output shaft speed sensor, a plurality of rotational speeds of an output shaft of the transmission, determining, by the controller, a shift time modifier based on the turbine shaft speed and a gradient of the output shaft speed, modifying, by the controller, a shift time for a pedal-off downshift of the transmission based on the shift time modifier to obtain a modified shift time, and controlling, by the controller, the pedal-off downshift of the transmission based on the modified shift time.

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Ann Arbor, MI, United States of America

Steven B Christ