A control system and method for automated mechanical transmission systems (10) of the type interpreting a first predetermined combination of parameters as a request or requirement for a direct shift to a predetermined default start ratio (GRDS) is provided. The control provides a predetermined series of actions by which the vehicle operator may manually select a new default start ratio such as, for example, by manipulation of shift selection device (1) displaceable in a first direction to select upshifts and in a second direction to select downshifts. |