Method for shifting from a source gear to a target gear in a twin clutch transmission

Gear shifts are carried out from a source gear to a target gear of a twin clutch transmission. The twin clutch transmission has sequentially directly successive gears assigned to different transmission input shafts. In each case one upshift and downshift threshold, which is defined as a function of the throttle pedal position, for each possible sequential gear change is stored as a corresponding vehicle speed value in a control unit. In case of a commanded downshift from a source gear to a lower gear, the target gear is determined in that the current vehicle speed is initially compared with the limit value of the closest downshift threshold, or of the adjacent downshift thresholds in the downshift direction, until the current vehicle speed is higher than the respective limit value of the most recently checked downshift threshold, in that, if, at the most recently checked downshift threshold, the higher gear of the downshift threshold is assigned the same transmission input shaft as the source gear, then the current vehicle speed is compared with the limit value of the upshift threshold which corresponds to the most recently checked downshift threshold. When the current vehicle speed is higher than the limit value of the upshift threshold, the higher gear of the upshift threshold is selected as a target gear. If the vehicle speed is lower than the limit value of the upshift threshold, the lower gear of the upshift threshold is selected as a target gear.