Vehicle bus

A vehicle bus is a specialized internal communications network that interconnects components inside a vehicle (e.g. automobile, bus, train, industrial or agricultural vehicle, ship, or aircraft). Special requirements for vehicle control such as assurance of message delivery, of non-conflicting messages, of minimum time of delivery, of low cost, and of EMF noise resilience, as well as redundant routing and other characteristics mandate the use of less common networking protocols. Protocols include Controller Area Network (CAN), Local Interconnect Network (LIN) and others. Conventional computer networking technologies (such as Ethernet and TCP/IP) are rarely used, except in aircraft, where implementations of the ARINC 664 such as the Avionics Full-Duplex Switched Ethernet are used. Aircraft that use AFDX include the B787, the A400M and the A380.

All cars sold in the United States since 1996 are required to have an On-Board Diagnostics connector, for access to the car's electronic controllers.

The main driving forces for the development of vehicle network technology have been the advances made in the electronics industry in general and government regulations imposed, especially in the United States, in order to make the automobiles environmentally friendly.

With stringent emission standards for automobiles, it became impossible to attain the required degree of control without the help of on-board computing devices. On-board electronic devices have also contributed substantially to vehicle performance, occupant comfort, ease of manufacture and cost effectiveness.

At one time, a car radio was likely the only electronic device in an automobile, but now almost every component of the vehicle has some electronic feature. Typical electronic modules on today's vehicles include the Engine Control Unit (ECU), the Transmission Control Unit (TCU), the Anti-lock Braking System (ABS) and body control modules (BCM).

...
Wikipedia