Adaptive pressure control improves the gearshift quality over the life of the vehicle. During an upshift, the slip times are measured and compared to a nominal value range. The mean deviations are then stored. As soon as a programmed limit value is exceeded, the pressure is increased or reduced in steps of 0.1 bar. In this way, the control system corrects engine scatter, compensates for differences in the friction lining and adapts to altitude.