Patent ID: 6248042
Filing Date: 2001-06-19
Classification: B60W,F16H,Y10T

Abstract:
A shift control method for automatic transmissions comprising the steps of:maintaining duty at 100% in a first speed of a drive D range, then determining if a first condition of a throttle opening being under a predetermined value during a first predetermined time is satisfied, and determining if a second condition is met during a second predetermined time, and if both the first and second conditions are satisfied, controlling duty to a first duty value then controlling duty according to a first reduction slope, after which it is determined if turbine rpm has changed;outputting a fuel reduction request signal if it is determined that the turbine rpm has changed, controlling duty to a second duty value then controlling duty according to a second reduction slope, determining if the turbine rpm has reached a predetermined standard value, controlling duty to a third duty value if the turbine rpm has reached the predetermined standard value, and maintaining duty to a fixed level and maintaining a neutral N range; anddetermining if conditions for releasing the neutral N range are satisfied, and if the conditions for releasing the neutral N range are determined to be satisfied performing control for shifting into the first speed of the drive D range, and outputting a fuel reduction stop signal such that the fuel reduction request signal is discontinued.