Method of shift control in an automatic transmission

摘要

A method of shift control in an automatic transmission having a torque converter and a shift-gear mechanism, wherein a shift map has a shift-up line and a shift-down line between each gear ratio change which is used to conduct the shift control, with a hysteresis zone being established between each shift-up line and the shift-down line. The method includes the steps of shifting down a speed range when a point representing a traveling state on the shift map moves in the lower vehicle speed direction and crosses the shift-down line, shifting up a speed range when the point moves in the higher vehicle speed direction and crosses the shift-up line, and shifting down the speed range when the point is in the hysteresis zone after a ratio of the torque converter has been shift and also the speed below a threshold level for more than a predetermined time.