In-vehicle networking provides many system-level benefits, many of which are only beginning to be realized.
" A decreased number of dedicated wires is required for each function, and thus reduces the size of the wiring harness. System cost, weight, reliability, serviceability, and installation are improved.
" Common sensor data, such as vehicle speed, engine temperature, etc. are available on the network, so data can be shared, thus eliminating the need for redundant sensors.
" Networking allows greater vehicle content flexibility because functions can be added through software changes. Existing systems require an additional module or additional I/O pins for each function added.
" Car manufacturers are discovering new features that are enabled by networking. For example, the 1996 Lincoln Continental's Memory Profile System stores each driver's preference for ride firmness, seat positions, steering assist effort, mirror positions, and even radio station presets.
However, for networking to expand into higher volume economy class vehicles, the overall system benefits need to outweigh the costs. Standardized protocols will enable this expansion. Automotive manufacturers and various automotive industry standards organizations have been working for many years to develop standards for in-vehicle networking. Many standards such as VAN, ABUS, CAN, and SAE J1850 have been developed, but SAE J1850 and CAN 2.0 (Controller Area Network) are the predominant standards.