CAN Bus

My point about ECUs being super advanced has a tiny little mistake from day before yesterday: While it's true that they are advanced, not everything is processed at the ECU; not since the Euro 5 emissions standard had come out.

Earlier, electronics in bikes, such as ABS, traction control, and quickshifters, etc. were connected to the ECU via something called the K-Line. All of them had a wire going out to the ECU, with each one having their own.

Interestingly, the K-Line is surprisingly old and seemingly ancient. Some of it's specs are:-

Now, Euro 5 emission norms required the bike to have an OBD port; this port allowed them to make the ECU more communicative. And in doing so, the manufacturers settled on a common communication standard - the CAN bus.

The CAN bus is a differential bus, which basically means that it uses two wires to transmit data. Out of these two wires, one is the CAN-High and the other is the CAN-Low. Instead of running heavy, independent wires to every single sensor and module, various ECUs (Engine Control Unit, ABS, Body Control Module, and Dash) broadcast their data across the bus. Did I say "various ECUs"?

Yes. The essence of having the CAN Bus is to allow for multiple computers to communicate with each other, and using general logic of "the closer the component, the faster the response", we have multiple Control Units control their aspects of the bike independently, but with the ability to talk to each other. There is, of course, the Engine Control Unit, which now controls primarily the engine itself, and there's the ABS unit controlling the braking system, the Display controller, etc.

CAN Bus allows for some pretty nifty features, such as being able to see error codes, trip information, service reminders, etc. It also allows engineers to send faults/error codes in a more standardised way, allowing for more efficient diagnostics and tuning. What's even better, is that the accessories that can be attached to the bike can also use the same protocol, so as long as it's wired to the bus, it can allow for a very integrated experience.

Cherry on top? It's a standardised protocol, in the sense that any company can use it, and it will work with any other company's product that supports the same standard (ISO 11898). Let's get into the nitty gritty, and know what the CANBus' specs are:-

The CAN bus allowed the motorcycles to be more "digital", but now also bringing distributed computing to something where you'd least expect. It gives a lot of freedom in terms of customising the bike, with almost native integration of accessories and not much hassle.