Abstract: The invention provides a method and apparatus for using the power line carrier of vehicles as a data bus. The scope of this invention is not limited to vehicles, but can be implemented in other applications that either have a power source or wired to one. In one embodiment, the invention uses the existing power line of a HDTTU to transmit data. An electrical component is coupled to the power line and transmits detectable signals on the power line. A second electrical component is also coupled to the power line and detects and decodes the detectable signals. In one embodiment, the signals are used to generate binary words that code information. In another embodiment, the power line of a HDTTU is used to carry sensor/warning signals from sensors placed on the vehicle to a display panel on the dashboard. Sensors are coupled to a control box which is used to convert the signals to a form that can be carried on the existing power line.