Shift control method for automatic transmission

摘要

A shift control method for an automatic transmission which includes converting to a lean-burn mode from a normal mode if throttle voltage is less than a first predetermined value; determining if tip-in has occurred in the lean-burn mode using accelerator pedal signals; increasing the throttle valve opening if it is determined that the throttle voltage has increased by a second predetermined value such that engine rpm is increased; determining if the difference between engine rpm and turbine rpm is greater than a predetermined number of rpm; and converting from the lean-burn mode to the normal mode if the engine rpm are greater than the turbine rpm by the predetermined number of rpm.