[mark] had an interesting idea when looking at all the wiring of a typical 3D printer; Use CAN Bus. There are a lot of wires going to the extruder assembly, and with most designs this thing is flying ...

The CAN bus, accessible through the OBD-II port, is the channel that holds all the secrets of the modern automobile. If you want to display those for your own perusal, you might consider this nifty ...