Vehicular power line communication system

A vehicular power line communication system, comprising:

• plural communication areas;
• electronic control units provided in the respective communication areas;
• a battery for supplying electric power to the respective communication areas;
• a power line coupling the battery and the respective communication areas to each other and for supplying the electric power to the respective communication areas;
• and
• branch power lines coupling the respective electronic control units to one another in each of the communication areas, the branch power lines supplying the electric power from the battery to the electronic control units, and superposing communication data thereon, thereby making data communication among the respective electronic control units,
• wherein the power line includes a +B line turning to a positive polarity, and a ground line turning to a negative polarity, the +B line and the ground line being cabled to be spaced from each other in a part of the power line.