Gear shift control apparatus

摘要

A gear shift control apparatus for use in an automatic transmission having friction elements each of which is operable on a working fluid pressure applied thereto in an engaged and released state. A change is produced from the current gear ratio to a desired gear ratio by increasing the pressure of the working fluid to a first one of the friction elements at a first rate to engage the first friction element while decreasing the pressure of the working fluid to a second one of the friction elements at a second rate to release the second friction element. A time elapsed for a torque phase in the gear ratio change is measured. The first rate is decreased when the measured torque phase time is shorter than a predetermined value. The second rate is increased when the measured torque phase time is longer than the predetermined value.