Practical Pico: CAN bus diagnostics and serial data decoding VIDEO
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- Опубликовано: 24 мар 2019
- Barney and Steve will describe PicoScope features and techniques you can use to diagnose faults in CAN bus systems. First, they will show you how to check the network physically and find common circuit faults. Then they will explore PicoScope's serial data decoding feature and how it can be used to examine CAN communications.
You can find the watch window for the following live session here: • Video
For more information about Pico Technology and our automotive products, please visit our website www.picoauto.com 
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WOW! Decoding the data. And this was just with the ABS including the brake pedal pushed on then off several times. The break down of the data packet parts shows how each module gets its data. AMAZING!
Thankyou guys for this video. I have to watch it again to understand it better.
This is super interesting and thanks for going to great extent to explain how to partially decode CAN signals. I still can't believe manufacturers still have these messages out in the open and not protected, very easy to introduce code and watch the vehicle react to it. Amazing video guys. Pico is revolutionary
I watched this live, and knew I would have to watch it again. An interesting, informative, and fascinating video. An incredible tool. Thank you for sharing.
Thanks, Andrew. Much appreciated.
Great job Pico Barney & Pico Steve very well done and an excellent explanation. I’m happy to add this to my video library.... Jay
Good information.
Clearly presented.
No nonsense.
It's channels like this one that make RUclips one of the best sites on the internet.
Great video, thanks!
I just got my first scope a few weeks ago, a Hantek, and I was trying to diagnose a CAN issue with the TCM on my car. The scope was fine for looking at waveforms but it was not much use for errors. The software was really basic.
Then I found out that Pico did serial decoding, like this, and I tried out the demo version, and pretty much immediately I immediately sent back my Hantek scope and picked up a Pico instead. The Pico software is just so much better.
Then I found this video and it just made it better again! It's always great when companies make detailed videos about how to actually use their products.. Fair play.
Muito bom e estas analogias nos faz sair um pouco das medições mais simples. São muitos os casos de mensagens e codigos de erros vinda da Can. Este equipamento de vcs são top demais .. é preciso uma vida inteira para saber mexer nele.
Great videos guys. Thanks for sharing here
Well explained and detailed great Job!!!
many thanks,enjoyed it. Thanks guys for your hard work putting it together.
A pleasure. Thanks for the feedback :)
Great job, Barney and Steve. There's a lot in this video, though I din't fall asleep. I liked the explanations which enable one to distinguish between different faults, and having example traces for each type of fault. Very well presented. Equally, I liked the walk through the serial data. Towards the end I was starting to think about other specific changes which might be identifiable, such as ABS pressure variations, as opposed to simple commands on or off. Just at this point the sound all but disappeared, though I believe you did briefly touch on this, as well as other possibles, like wheel speed information. (Must listen again !) )We keep hearing that serial decoding doesn't have any real use in diagnostics, but I get the impression it does in certain circumstances - especially if you can identify identifiers, and use the other 'simple' tools within the software - and Excel - to filter. Still, a fascinating subject and this really helps to better understand just how much serious 'waffling' is going on at any given moment among all the different 'passengers' on the Bus. I was at the back of the Bus so didn't take it all in, lol Look forward to the next one. Thanks.
Thanks for taking the time to give your feedback, David. Much appreciated!
KNOWLEDGEABLE PicoScope Automotive
Thank you very much helpful video
PicoScope Automotive
From Nick Ayivor from London England UK 🇬🇧
GREAT EXPLAINATION
Awesome!
thank for video
Nice video
I really want to have a tool like this one and also learn to use it , very interesting,
I completely get the concepts in this tutorial. But, question, is this to determine a faulty module on the network? Also, are the circuit tests in the beginning common failure modes to look for?
Amigo excelente práctico útil tu video preg donde consiguen los Diagramas d obd 11 y d ECUS sensores módulos etc gracias por ayuda he informacion
Thanks for the video! I am in the process learning with my pico 2205. Where can I but the ground leads you used with the pin on them to plug into my Breakout box?
It is interesting, but it is pretty deep and tough to follow for this lowly tech. I do like going deep into diagnoses when needed, but I’m a little confused to what kind of problems or performance issues that this deep dive would be used for. Can you give us a few examples of the type of problems that this would help with? Thanks
Thanks, Every car as a TIPM central gateway circuit board which has Microcontroller chips and Transceiver chips which all the modules connect to the TIPM circuit board? I'm not sure what this TIPM circuit does can you explain more about TIPM circuit boards? When you get a checksum error how do you know if its the transmitter or the receiver because both or one or the other can cause a checksum error, so how do you troubleshoot to know if the transmitter is causing the checksum error or the receiver is causing the checksum error? The DLC connect has SAE J1850 signals and ISO9141 Signals, do you use these to troubleshoot failures in cars or what are these signals used for?
Nice video how can i find the can bus and my 2018 honda accord i missing 120 ohm i only have 120ohm at the gateway module
Also, are there common IDs in the CAN bus protocol that would speed up a technicians diagnostics?
Nice BMW for 2019...
Are we seeing a complete DC voltage switching?
If this Picoscope model came with an arb gen and had an alt trigger function I'd buy one instantly.
Just on the missing resistor scope test, it is a good idea to keep an eye on voltage on the CAN bus lines.
True though I’m sure they know.
Thanks excellent video keep up with your great work 👌,,, price on scope to test ,,crank sensor,, or injector connecters thanks
Hi, thanks for the video.How could you relate a problem to the various CAN faults you listed when an car would stay on one gear without shifting and when you turn off the engine and restart the car, the car starts shifting fine. What can faults could this problem fall into. Thanks.
Hi Paul, The question is: are you getting CAN-related DTCs when you do a full scan of all the vehicle ECUs? If you are getting transmission-related CAN DTCs then, possibly, suspect a CAN-related fault causing the problem you describe. If you don't have those DTCS, then you may be jumping to conclusions. I.e. what is it that makes you think that CAN is responsible for the symptoms you are seeing?
The car probably has a bug within the software that is dealing with shiting gears, that acta like you noticed.
At first start of engine comes one (the bug) at next start everything is clear and nice.
Got to manufacturer and exlaind and ask for an update of the gear-shift module or to rewrite their software again..
Is it possible to carry out the same tests but with the 2206b scope please? I really would like to add this to my diagnostic bag but can't afford the automotive series?? Great video by the way, info from the pros, 1st rate👍🏻
Hi,
Thanks for the feedback which we really appreciate.
The quick answer is that yes, it is possible to carry out those tests with a 2000-series scope as long as you have sufficiently high bandwidth and sample rate.
Beyond that, I'm afraid I can't support you with more information as the automotive team cannot support users with 2000-series scopes as they are not automotive products.
Some related info that might be relevant...
I appreciate that the automotive products seem more expensive at first glance but by the time you add equivalent accessories and specs - including upgrading to a higher sample rate model and adding attenuators for all the channels etc. - the difference is not so great. This is especially true if you compare the cost of an automotive kit to buying all the components individually.
Note that you can never actually achieve parity between the 4x25 scopes and the 2000-series as the former have floating inputs, 12-bit resolution (compared to 8-bit), and a ruggedized boot etc.
The difference in price also covers the Guided Tests, Waveform Library and PicoDiagnostics plus, support email/hotline availability, and online videos/articles etc that come with the automotive scopes. So actually you get an awful lot extra for a small increase in price.
As a former tech, I can totally relate to the difficult investment decisions we have to make (especially at this very difficult time) when you are trying to better yourself and the skills you can offer. But, hand-on-heart, I believe that starting off with the better tool will save you money in the long run, even if you have to wait a little longer before you buy one.
I hope that helps. Good luck on you oscilloscope diagnostics journey!
Barns
@@pico_barney Wow, what a great answer, I can see now the worth of the automotive series scopes and what now seems good value. Looks like I need to do some overtime! Thank you very much for the reply and keep up the very informative content 👍🏻
would an audi a5 connected with a breakout box and just ignition on show canbus activity?
I'm interested in the rolling cart, where can I get one for my scope?
Hi , It depends on which rolling cart you are talking about. The cart used in the shot with Barney (black unit) is a Ctek battery test unit supplied via CTEK. The red cart is an emmission tester trolley supplied by our Danish distributor (not avalaiable anymore) or the black tool box are purchased by Sonic tools in the Netherland. Hope this helps Philip
Just ignore the guided bomb hanging from the joist in the background @ 6:45.
Pretty sure that's a torpedo
What is the exact model number of the device used in this video ? And could we do the same things on a lower models like 2 or 3 series ?
A 4425 scope was used to perform this test. Of the current automotive scopes we sell, you could use a 4225 (2-channel), a 4425 (4-channel) or a 4823 (8-channel). Of our older automotive scopes (no longer available from new), you can use a 4223 (2 channel) or a 4423 (4 channel). The bandwidth (10 MHz) of our older 3000-series automotive scopes is too low to reliably perform these tests.
Hi where an I get the laptop stand to buy ? Thanks
BARNEY DONOHEW, how did you create "OPEN circuit module" you disconnect the CAN signal Low signal and only left the CAN High signal active or how did you create OPEN circuit CAN signals? My other question is most modules are hard to get out to disconnect without tearing the whole car apart. Can't I just remove each fuse at the cars fuse box one by one until the CAN bus signals returns back to normal? When measuring a CAN signals how can you tell if the CAN signals are 2.0A, 2.0B or CAN FD because they all look the same to me so how can you tell the differences so i know what to set the CAN Baud rate to? If you wanted to upgrade from CAN 2.0A to CAN 2.0B to CAN FD all you have to do is replace all the CAN transceivers to CAN FD transceivers? the CAN buss harness stays the same and all the CAN ECU modules stay the same only the CAN transceivers get replaced?
Hi Bill, the answers are as follows:
i) we disconnected the ABS module but then put break-out leads on CAN-L and CAN-H between the module and the loom. This meant we lost ABS communications but were able to maintain bus integrity. Obviously, it was then easy to access the lines to create short and open circuits and to introduce high resistances etc.
ii) Pulling fuses could work. So could analysing any DTCs to give you an idea of the problem nodes in advance, which you could then disconnect as you scope the messages (as you mention above). You'd then be well placed to start circuit checking in the right places if need be.
iii) You don't need to worry about standard (2.0A) and extended (2.0B) CAN IDs. PicoScope Serial Decoding will take care of that for you.
iv) The data payload within the middle of a CAN FD frame is at a noticeably higher bit rate that the surrounding message (which contain the ID and ACK portions of the frame). So you will see 'more switching activity' in the middle of a CAN FD frame compared to the parts on either side. You will need to look out for this difference and, if it exists, select CAN FD rather than CAN serial decoding.
v) You can't add CAN FD messaging into a legacy network (where the controllers within the other nodes are expecting classic CAN). If you want to have a mixed CAN and CAN FD network the classic CAN controllers need to be CAN FD tolerant (i.e. they need to understand that it is present, without actually being able to transmit/receive those messages). CAN FD controllers can transmit and receive both classic CAN and CAN FD messages.
Hope that helps.
Серия PicoScope® 2000 can this oscilloscope model work with can ?
help me choose the most inexpensive oscilloscope model to work with the can data bus
how to diagnose a complete dead car?
not bad battery
anyone else noted the torpedo in the back at 12.07?
Anybody notes the torpedo in the background? 😀😃
Yes, this comes from a James Bond film set. Got the video in the garage .
This is a good how much price
Serial decoding is a feature of our PicoScope software, to which you have free access (and updates) when you buy a PicoScope (www.picoauto.com/products/automotive-oscilloscope-kit/overview. Hope that helps.
@@xFrShizzLEx Good catch. Thank you. Have edited my link too, just in case.
@@pico_barney You guys are doing a great job! I'm just a shade tree mechanic, but I can see this is where technology is going if you truly want to keep doing it yourself.
@@pico_barney My current problem vehicle may have a bad transmission shift solenoid which seems to hesitate and stumble while shifting gears. I figured I would just change it based on physical symptoms. Are you able to test for that too?
@@xFrShizzLEx only non mechatronics
PICOSCOPE Automotive, The CAN Bus has voltages and decimals values but how does a technician know they are good or bad CAN bus signals? What are the most common CAN Bus failures that a technician looks for? and you give more examples about this
Hi Bill, thanks for your comment. We show quite a few 'normal' signals in the video (e.g. at 13m40s). These are always a good reference point: anything that doesn't have that same regular structure should cause suspicion and prompt further investigation (e.g. checking bus resistance in the first instance and then more detail circuit testing). Our PicoScope Automotive software contains a more detailed description of these waveforms (within the built in Guided Tests) if required. Regarding faulty signals, go to 13m55s in the video and you will see that we run through over half a dozen different examples of possible faults and the associated waveforms. The main thing to remember is that CAN buses are just circuits: they will be susceptible to open or short circuits or high resistance. If you know how to test for these on other circuits then you will know enough to test a CAN bus. :) Hope that helps.
If it decodes without error it is good
este equipamento e top, pena que não tem no brazil. Aqui só temos lixo
Hi Senhor Ateu, thank you for your interest and praise. We do have some distributors in Brazil. Please take a look at our list of distributors here: www.picoauto.com/distributors
34:00
What are CAN sniffers used for to do what or what have you used them for? Dodge & Chrysler cars use TIPM boards, How does a TIPM totally intergrated power module or central gateway work what does it do? There is different CAN signal names, CAN diagnostic, CAN isolation, CAN ground, what else?
Hi Bill, thanks for this comment and the others that you have left throughout this list. We are happy to help with points of clarification on items within the video and with matters relating to the use of our scopes. For other matters, please feel free to seek help from the wider community on our online forum (www.picoauto.com/support/index.php). However, it may be useful if you find other opportunities to undertake training or self-learning - it will pay you back, I promise! Also, please try the manufacturer's reference material for the highly specific information you have requested. Best regards, Barney
That resistance is only on the circuit between the other terminating resistor and your test, it dose not confirm the other modules in parallel have a good circuit at all. You may have a dash cluster or radio infotainment system that has a broken line to them and don’t run the other resistor, they now have not been tested, it’s important to know this, if you have a faulty ABS because both of these lines are needed for different functions from the ABS.
The basic electrical level error detection detailed at the beginning is useful, but the majority of the video dedicated to decoding the CAN bus data doesn't seem practically useful for the average technician trying to diagnose faults. I really feel like I wasted an hour of my time watching this video.
Lets conclude this.
In the clip it is proven to us that we can see on the computer screen the BUS-CAN comunication ...when one of the module dissapear.. and make note of that.. bla bla bla.
The author it is trying to pursue us to buy that specific module to check very much what he checked and conclude NOTHING ..when it comes to findind a very specific fault (should I say unic fault..?) which you wish to find..
This is pure science with NO solution yet..
You can buy this very specific osciloscope but, BE CARFUL, might become or is obsolute for newer car because the inteface cannot keep up with the transmission speed within CAN BUS.
BMW E46 i think is the last model before bmw decided to fit optical fiber on their cars for audio (basically sending MULTIPLEX SIGNAL USING ONE SUPPORT -OPTICAL FIBER!) and communication with their iCOM test modules..
Buyers beware!
In clip is NOT mention too much about this...
I know I will be hated for that, but fairness must win.
Hi, Sorry but I can't follow your logic. Can you clarify what you are saying because it is incoherent? Every professional technician will know that there are other types of networks on vehicles. This video doesn't need to discuss those because we are trying to help technicians with the hundreds of millions of cars worldwide (including post-E46 BMWs) that use CAN networks. Also, there is no additional cost to the serial decoding feature: it is built into our PS6 software (and it will soon be in PS7). So I am wondering why you are trying to suggest that we are misleading our customers (potential or existing)? Because that is a defamatory statement, if so.
@@pico_barney Barney, I think I know what he means, because he put into words what I was trying to. The whole video seems to show only the decoding in detail, but doesn't give a worked example where such knowledge would be of any use. It would be nice to see a raw example of the technician using these codes to solve a real problem, without the technician having had hours of time off camera to figure out the fault. A real fault would be good as opposed to a fault that has been purposely introduced. I know you have a video of a network failing when the dashboard gets a thump, but I don't think the decoded value is really relevant in fixing that problem either. I'm not knocking Picoscope by the way. I have two and I love them. I just came here looking a case where the code values are useful in solving a problem, but haven't seen such a video yet. Perhaps you would point me to one if there is one. Thanks
Might be a good tutorial if I could understand what you are saying. Please don't mumble into the module. Speak clearly into the mic .
So you can do the same thing with an affordable DVOM that a three thousand dollar kit can wtf who uses this shit use a meter if everything looks good and other modules can communicate bad device simple........ I work for a busy dealership and this shit is not needed........
dealer techs don't diagnose they guess
@@712gln they dont diagnose...they ask their coworker for help and if that doesnt fix the car then they call the technical support hotline😁
Where do you get the little adapters you put on the end of the leads before putting them in the breakout box?
Hello and thank you for the feedback. These adapters can be found here www.picoauto.com/products/clips-and-adaptors/shrouded-to-unshrouded-adaptor