Start ratio engagement control system and method.

摘要

A control system and method for a vehicular semi-automatic mechanical transmission system (10) is provided for allowing controller or operator request for a direct downshift into a preselected start ratio, under certain predefined conditions. The direct downshift into the preselected start gear ratio is sequenced such that the target synchronous engine speed (OS*GR) at target gear ratio engagement is substantially equal to a preselected desirable, preferably constant, value for all selectable start ratios.