ON-VEHICLE CONTROL SYSTEM AND CONTROLLING METHOD OF ON-VEHICLE CONTROL SYSTEM

An on-vehicle control system includes lower level control units (30-1 and 30-2) each including a driver circuit (34) capable of driving each of a plurality of loads and a multiplex communication circuit (31), an upper level control unit (21) that is connected with each of the plurality of lower level control units via a predetermined communication line (41) and controls the plurality of lower level control units. A first lower level control unit (30-1) and a second lower level control unit (30-2) are connected as the plurality of lower level control units. The upper level control unit includes a function allocation unit (22 and 23) that allocates a first function to the first lower level control unit and allocates a second function to the second lower level control unit, and a master control unit (24) that controls the first function and the second function by communication.