Vehicle engine and transmission control system

摘要

The system has the engine control (2) and the automatic transmission control (4a) interconnected by a communication channel or bus (6) whereby data are exchanged between a smart ratio change unit (4) and some chassis- or engine-specific functional units (5) of the transmission control which are integrated into the engine control. These units include ratio selection logic (11), a classification of driver behaviour (24), a diagnostic circuit (25) and a basic data input/output module (26). The smart ratio change unit includes an emergency section (34) enabling control signals to be supplied to it independently of the bus when the latter is found faulty.