The Controller Area Network (CAN) had the honor of winning the race to be the OBDII standard and of being the best technology; something that doesn’t always happen with technology. This means that since 2008, the CAN system has been the only OBDII computer system installed in new vehicles.
The CAN system can be visualized like a business inside of a car. The engine controller, stereo, doors, all electronic systems aboard the vehicle are connected. The CAN is like the CEO. It gives the orders and makes sure that the car is running correctly. Throughout the vehicle, there are several LIN-bus systems (Local Interconnect Network) that manage smaller functions. If the driver window needs to be rolled up, the CAN tells the LIN that it needs to be rolled up, and the LIN controls all of the functions needed to roll up the window, saving the CAN from using resources it might need elsewhere. The LIN is like a manager instructing the interns on a project rather than having the CEO use his or her time micromanaging.
The CAN standard is the fastest of all of the previous forms of OBDII systems, which were mentioned in my previous post. It has the ability to manage many functions at once, but new cars have new features, and new features take computing power. Heated seats, de-icing side mirrors and tire pressure monitors take resources too, and even the mighty CAN is beginning to feel the strain.
Just as USB 2.0’s impressive advantage over USB 1.0 is now giving way to USB 3.0, OBDII computers are approaching the point where they will need a faster and more powerful alternative to CAN. The next standard will likely be Ethernet, chosen for its high bandwidth and speed, as well as its proven record of reliability.