Shift Control System and It's Method for Automatic Transmission

摘要

Quick shifting is achieved while preventing a shift shock when shifting is caused by grip change of four engagement elements. This automatic transmission requires activation of the four engagement elements when shifting from a first shifting position (sixth speed) to a second shifting position (third speed) is performed. This shifting control apparatus includes shift control means for starting disengagement of a second engagement element C-2 after starting disengagement of a first engagement element B-1; completing engagement ofa fourth engagement element C-3 after completing engagement of a third engagement element C-1; and starting disengagement of a second engagement element C-2 before completing engagement of a third engagement element C-1.