in order to enable a more rapid shift and to prevent tie - up from occurring when a down - shift occurs during an up - shift , an amount of overrun produced during the down - shift is detected , and a hydraulic duty for an engaging element of the down - shift is modified by performing one of adding and subtracting a correction value , the correction value being calculated based on the detected amount of overrun , such that the amount of overrun will converge to a predetermined minimal level .