Verfahren zur Schaltsteuerung eines Automatikgetriebes

摘要

A shift control for a shift-down operation is executed by carrying out the following stages in order: an off-going range releasing stage STO1 which quickly lowers the engagement actuation pressure of the off-going engaging element to an engagement-releasing pressure; an off-going range controlling stage STO2, STO3 and STO4 which sets the engagement actuation pressure of the off-going engaging element to a pressure a little higher than the engagement-releasing pressure; an on-coming range void-stroke-clearing stage STR1 which sets the engagement actuation pressure of the on-coming engaging element to a predetermined high-pressure necessary for clearing the void stroke; an on-coming range waiting stage STR2 and STR3 which sets the engagement actuation pressure of the on-coming engaging element to a stand-by pressure necessary for retaining the on-coming engaging element in stand-by condition prior to engagement; an off-going range final stage which releases the off-going engaging element completely; and an on-coming range final stage which engages the on-coming engaging element completely.