CAN Bus Explained - A Simple Intro [v1.0 | 2019]

UPDATE: Check out our new v2.0 intro to CAN bus!

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What is CAN bus?

In this intro we explain the basics of CAN, incl. advantages, history, messages and the relation to protocols like J1939, OBD2 and CANopen!

For a quick intro to our CANedge CAN bus data loggers, check out the below!

In short, the Controller Area Network (CAN) is a standard used to allow Electronic Control Units (ECUs) to communicate in an efficient manner without a central computer.

Messages are broadcast in a system that requires very little physical wiring making CAN bus low cost, robust and efficient.

Applications of the CAN protocol include in particular automotive (cars, trucks, buses, commercial vehicles etc.), but also e.g. boats, drones and industrial automation.

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INTROS TO CAN BASED PROTOCOLS

This video is part of our extremely popular series of CAN protocol intros. Below you'll find links for our full playlist, as well as the more detailed articles.

Tip: Want all our CAN intros in one 100+ page PDF? Then get your free 'Ultimate Guide' now:
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RECORDING & DECODING CAN BUS DATA

If you're interested in learning more about logging CAN bus data, we recommend that you check out our below intros to our CANedge CAN bus data loggers, our CANmod sensor-to-CAN modules and our free software/API tools:

Learn about CAN bus data logging:

Learn about the CANedge and CANmod:

See also our full intros to practical data logging:

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ABOUT CSS ELECTRONICS

At CSS Electronics we specialize in simple-to-use, pro specs and interoperable CAN bus data loggers - like the CANedge and CANmod series. The devices let you record raw data from e.g. cars, trucks, industrial machinery and other CAN based applications onto an 8-32 GB SD card. The devices are interoperable, meaning you can process the data in your favorite existing software - or use our 100% free and open source software/API tools.

We offer 100% free technical sparring - contact us:

[anomalous]

This was by far the best explanation of CAN bus I've seen so far. I already watched a handful of CAN videos after starting to research but this put a really clear explanation in my mind, thanks for this awesome video!

[thommytwotoestimesthree]

Good job. I think. Not sure if this is in laymen's terms but when i sober up i'll take another listen.

[drcvagos-iu]

finally a video speaking my language, I really appreciate the art of keeping things simple... :)

[draven]

Gotta love when theres a short in the obd2 cable you're using, the car shits itself and the whole dash lights up like a Christmas tree. Ask me how I know

[lucarioind]

I found it simple and well explained
Guys pleae try to keep your head into technical trends rather than stupid social media....that way you can understand

[blackmanops]

How about a mention of the actual physical embodiment rather than showing pictures of totally irrelevant things. For a layman's intro, I still don't know how many wires, how long wires could be, what the voltage signal levels are, or if it is even voltage driven and not a current loop (ala MIDI). Otherwise a solid explanation of the data layer and the history.

[Sparky]

We've completed a test can model that uses dynamic identifier streams when certain bits aren't required. It has increased efficiency a great deal.

[flomondbarnes]

Simple it's all about speaking a new language to communicate, the problem is learning how to speak the can languages, good video thanks .

[patricksandiego]

I am poised to help a customer using this interface in their telematics solution, so thank you for the detailed simple explanation.

[aaronlowe]

This was EXTREMELY informative. After I got a synopsis of what it was, I wanted to know how it communicated at the bit level. And this video explained EXACTLY that in a very comprehensive way. Perfect job. Thank you.

[tomthumb]

Great explanation of how CAN works but still needs refining, as some of the terms are too technical for the average guy to get to grips with when rushed through like this. Excellent for those with basic understanding of computer technology though and very informative. I’ve subscribed straight away, as I can see the potential of these explanations. Thanks.

[padams]

I never imagined how annoying the use of “e.g.” could be...

[ingeniousmechanic]

In other words, when the warranty is out, you're done

[johncooper]

good guide but the background music is far far too LOUD . irritating and makes it difficult to hear the narration

[ratbrain]

If that was laymans term. I must be the missing link knuckle dragger.

[ozzstars_cars]

This video would be much better without the annoying background music.

[evanriddle]

Crank turns, valves ain't stuck. My nephew and I drive cars away sitting dead for years on the end of dirt roads. Time to upgrade our skills. Thanks!

[richardjelinek]

Among your key reasons "#2 Centralized" is quite wrong as it's pretty much the opposite. CAN bus is a multi-master (= decentral) bus system. The feature "allows for central diagnosis and configuration" is simply because you can plug in "just another node" that listens to the bus and interprets messages. And - because it is decentral - can also send (configuration) messages.

[TediumGenius]

Thanks for a well-balanced introduction into this technology! I have an ODBII reader and have used it for both DTC retrieval but also for real-time data. The interesting thing about CAN is that it is similar to XTML scripting (website and other networked data) in the sense that it is eXtensible.... to a point. The data structure is familiar, especially to me via an understanding of the old AT telecommunications Command Set protocol. And I suppose if you know serial or parallel digital communications, PLC integration, etc... that is a help, too. BUT I could understand this even without that background- I needed the video to make the correlation between these. Thanks again!

[unknownriderinbound]

Lost me with the human body analogy- isn't that an example of a host computer with a highly complex wiring system and prioritization conflicts? I wish the body had multiple ECU's, if my walking and gum-chewing nodes could communicate directly I might actually be able to perform both functions at the same time!