Control system for selectively switchable two/four wheel drive automatic transmission system providing shifting characteristic matched to driving condition

摘要

A transmission for a vehicle has a main transmission system which can be set to any one of a plurality of speed stages, and a transfer transmission system which receives power from the main transmission system and can be selectively set either to a two wheel drive operational mode or a four wheel drive operational mode. A transmission control system for this transmission incorporates a means for detecting at least one parameter representing the operational condition of the vehicle, a means for determining the operational mode of the transfer transmission system, and a means for automatically setting the main transmission system to selected ones of the plurality of speed stages thereof according to the parameter representing the operational condition of the vehicle, and also according to the operational mode of the transfer transmission system, wherein the pattern of shifting between the plurality of speed stages of the main transmission system according to the parameter is varied, according as the transfer transmission system is set to the two wheel drive operational mode or the four wheel drive operational mode.