Ford Global Technolgoies, LLC

Michael Tarrant

Kevin MacFarlane

Barbara Anne Hartline

Than Pham

Douglas R Cecil

Timothy Merlino

Vince P LaVoie

Mark A Smith

A method for controlling a coast down downshift that is produced in an automatic transmission by disengaging an off-going control element and engaging an oncoming control element, including the steps of determining a first desired pressure magnitude of the off-going control element and a first desired pressure magnitude of the oncoming control element, executing the current downshift using said first desired pressure magnitudes, determining during execution of the current downshift corrections of said first desired pressure magnitudes that occur during the current downshift, determining a second desired pressure magnitude of the off-going control element and a second desired pressure magnitude of the oncoming control element, using said corrections and the second desired pressure magnitude to determine a subsequent desired pressure magnitude of the off-going control element and a subsequent desired pressure magnitude of the oncoming control element, and executing a downshift using said subsequent desired pressure magnitudes.

Avoiding coasting downshift torque reversal in an automatic transmission

A method for executing a downshift in a transmission includes starting disengagement of a second control element after starting disengagement of a first element. Disengagement of the second element starts before starting engagement of a fourth element. A third element is forced to synchronous speed by beginning engagement of the fourth element before engaging the third element. Engagement of the third and fourth elements is completed at the end of the downshift.

Control of sequential downshifts in a transmission

Growing community of inventors

South Lyon, MI, United States of America

Michael Tarrant