Got a “Network car”?
Just like your home and office network system that connects multiple computers and devices to each other thru a router (gateway) for file and connection sharing – so do today’s cars – with some having 5 networks or more!
YUP – they’re called “Controller Area Networks” (CAN) – first introduced on cars back in 1992 by MBZ, and is basically used on every car built today.
For example, one basic network is the PT CAN – it’s for the power train, which connects (just to name a few) the transmission, engine, fuel pump, & drive away protection modules (computers), to one another, and taps into some the many BUS systems (information highway – aka internet) that carry multitudes of sensor data (files) for all modules on that network to share.
For instance – the RPM signal from the engine’s crank position sensor is used by the transmission for shifting.
Car networks aren’t wireless yet – they’re built using line topology – meaning cars use same colored wires (per network) that tap into the BUS (internet) and connect modules (computers) to one another at specific splice connectors.
There can be as many as 28 modules (computers) on a single CAN (network). With each module connecting to it’s network by a 2 wire setup and meeting up at one splice connector means a lot of wires routed throughout the car and thus having the possibility of much compromise. So it just takes one of those 28 modules (computers) or two of those 56 wires to develop an open or short circuit which can take out that entire network completely!
There is much training involved to know and diagnose these ever changing network systems. Hollis Brothers Auto techs always keep up on the latest changes.
Every year a new or revised CAN system appears, new approaches in diagnosing are established, and more common failure patterns are learned.
Happy car networking to you!