CAN Bus Troubleshooting and Diagnosis Explained (Part 3) 

I’m mechanic for Caterpillar. The enhanced understanding I gained from your series allowed me to repair a Grade & Slope system on an asphalt paver that nobody could figure out. Thank you so much for this!

you sir are the goat. Im, currently doing a harness merge on my 00 subaru and learn as i go. For the past weeks i've learn to myselft how to read the subaru diagrams and what they ment and how they work. And when you showed a subaru wiring diagram on the video, I quickly went "is that a Subaru diagram?". And it was so funny to me that, it is and i quickly recognized it 😂. Canbus does not really apply to what im working on right now. but for future reference (my 08 rx8 that has a canbus system) , really gave me a full understanding on how newer cars work and gave me ideas on how to diagnose these "new systems". great video series. I definitely learned a lot. 👍👍

Hi? Am from Africa Zambia in particular,and I would love to send you flowers for your extraordinary efforts to make your lessons teacheable🎉🎉🎉🎉🎉.

Great Part 3 - Overall great Class in total - Hope we get another one some day sooner or later.

Awesome series. It can be so helpful to an occasional weekend warrior like myself to simply understand how some of the systems like CAN even work. It's nice to know I should have at least a general idea what I'm even working with when trying to find a problem. Thank you for this awesome series, and especially for part 3 for tying it all together with a real world example. This was a few hours of my time very well spent!!!

Knowledge + Experience × Passion ÷ Humour = Awesome Tutorial ! Thank you so much Ryan

Really good series. I have learned to appreciate the more complex network designs ever since I had a short in an air conditioning system cause a no-start by pulling down everything on the network. It then became apparent “ohhhhhhhh- NOW it is clear why a gateway is useful!!!”

Im a DIYer and these 3 classes were helpful in an astronkmical way. Quick note, when you were checking the JC near the pillar for short to power and short to ground. Me being a beginner, I wish you would have told us what we would see if it WAS shorted to power/ground/eachother. I subscribed!

Props on a great series Ryan! All 3 parts so far were easy to watch and more importantly, easy to understand. Your teachings have allowed me to sharpen and hone my skills when it comes to CAN diagnostics and repair. Thanks for your time, I'm sure it's not easy putting these tutorial videos together. 👍🏻👌🏼

Thank you for making this 3 part series. Very useful . Your efforts are much appreciated

Great job Ryan! As a part time trade instructor, running a business and a RU-vid channel, it can be hard to explain to students the diagnostic process. Thanks for an excellent 3 part series, which logically broke down the process into manageable sections. It has given me some great ideas to include in my classes. Cheers MiracleMAX

I am not a technician, I just play one on weekends and your 3 part series was excellent that I just had to leave a comment to express gratitude for all your work in putting it together. Thank you.

I watched your series just to understand can bus better in general for a custom project. Now I want to be a mechanic when I grow up! :D Thank you for the excellent walkthrough.

Thankyou for helping me understand can bus diag better. You have helped me alot. I am greatful for people like yourself for sharing your knowlage with people who want to learn. Keep up the good work.

Great video. I'm working on a PT Cruiser right now with other electrical errors. Not a CAN problem, but I used its communication schematic to follow along with you. With your help, I was able to see how it worked and how to troubleshoot it if I need to. This has to be one of the BEST educational series on RU-vid.

Best Investigator for Wiring Faults on the CAN BUS network👋👌✌🤘.

Just watched this series and i must say it was one of the best ones so far, explaining the different systems 👍

Thanks Ryan! I started to get lost when you were explaining the wiring diagram and comparing it with the car. But after I went back and studied it more I was saved, lol. Thats just a matter of experience and I have about zero with Can networking. Your videos helped me understand how the systems work and I have a little bit of confidense now. Thanks again.

DANG! This process has been fun to watch. Thank you for sharing your expertise on this topic. Outstanding job on the whole series. If you want to continue on other vehicles/systems, I'll be tuning in just as intently as this one... Thanks again!

Amazing 3 part series. Many Thanks -- A BIG help for this old timer. More can videos would be greatly appreciated !!!!

Great classes and good explanation Ryan and thanks for teaching 🙏God bless you

awesome case study , great video step by step ,including wiring diagrams. good job

Great series, I started working on cars when Ford had the eek series. I don't do it anymore but do mess around when i can pick up a cheap car to mess with. I still got it so far.

This is one of the best can bus video

Hi Ryan: Data bus is a A Must to know in the future, I have kicking up a notch on how data bus systems work after watching your videos. A quick and dirty way is to look up the wiring diagram to located which modules have resistors and do a ohm test on it follow up by substituted 120 ohms resistor to make sure all other modules are good. Thank you so much.

NISSAN AND KIA ,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,, COULD POSSIBLY HAVE YOU WEEPING .OUTSTANDING CLASS THOUGH AND YES WOULD LOVE TO SEE YOU TRY TAKING THEM ON BECAUSE THEY HAVE PROVEN TO BE SOME OF THE MOST DIFFICULT NETWORK CRASHES OUT THERE. PLEASE KEEP UP THE GREAT WORK THANK YOU!

yes bro , cant wait to watch this , your teachings is truly epic , keep the classes coming , really appreciate the knowledge .

Excellent!!!!! Your diligence and passion for teaching is greatly appreciated by all of us who are in the automotive field , l am sure. Stay healthy and Happy, always.

Watched all the three parts. one of the best out there in youtube. You are a great teacher. Thanks alot for making this series.

Thank you for teaching me how to understand all of this, I'm from Mozambique and because of you I will change the way people diagnose most of the cars here, btw I'm focused in bmw and merc cars..

Thanks ! This is making sense due to this fantastic series of lessons ! You have a real gift for coaching !

Another solid lesson down. Tank you. Brilliant lesson and practical application of the previous lessons.

Great Educational series on CAN networks! Thanks for your time and work you put into helping teach people a better way to look into diagnostics of these systems.

Really, really good video enjoyed every minute of it. Thank you so much for your clear , timely interesting and informative presentation........great job!!!!!!

Awesome series, Ryan! Didn't miss a single second. When I first started watching, I had no idea about CAN bus. However, you managed to open our eyes and help us learn everything from the grassroots level. Thank you very much for sharing your knowledge, experience, and time with people across the world. 👌 - A guy from the other side of the world

Best video series I've seen so far!! I've applied what I have learned from your videos, but I am still a little unsure of my diagnosis. I have a 2013 S550 4matic with the do not shift error. Scanned the system and got no can message for about five different modules but no faults in the gateway module. I think the problem is the gateway module. The voltage and resistance are good on every can connection. I don't have a scope yet. It's in the mail.

Excellent presentation of your wisdom and passion for empowering and encouraging many enthusiasts out there. Your understanding and knowledge of what you do is fantastic, and I definitely learned a lot from you videos. Thank you very much.

Hello Ryan, I really enjoyed the classes, they were both excellent in theory and in practice, you are an exellen insructor , I learned many tips that I will put into practice. Thank you

Thanks, I learned so much from your video. I love how in depth you went. I will now try and solve my can buss issue in my 2006 raider. I will let you know how it turns out. I will also revert to your videos if I run into problems. Thanks for all the time you took to make these videos. Outstanding!!!

Excellent series on this subject, I will be encouraging all of our techs to watch! One comment on your technique for checking CAN line short to power using continuity to pin 16 of DLC with the battery disconnected. In checking this way it will show a short to any 30 feeds but this test excludes any possible short to power to the fed side of any switched power circuits.

Thanks! 35 year tech. I watched all three parts and it is the best explanation of network theory and diagnosis I've seen. Got a lot of info through my thick skull and cleared up some fog in my old brain Thank you!

Awesome video for those both in experienced and experienced, well explained! And learned a bit along the way thank you

Thank You, i have found this informative. its slow at work today so i thought i would reinforce my diagnostic skills. your method of adding a resistor seems to be a very useful process that i will certainly take advantage of in future diag. i have had a few communication failure jobs in the past couple weeks, 1 - 2007 pci bus and 1 - 2017 can bus issue and i found myself learning more than diagnosing. This series will definitely save me some time later. subscribed

Followed all 3 parts got a lot out of these thanks

Might have been a good idea to check terminal resistor in PCM itself at pins A58 and A45 just to be 100% it isn’t a pin connection issue but evidence was overwhelming anyway.

Excellent 3 part lessons. You also did most of the testing without reverting to expensive tools that most vids feature. This is so important for us non-professionals needing to trouble shoot.

Thanks for posting this entire series. I'm a DIYer, facing odd issues on family member's cars with communication loss popping up commonly, and while I was aware of Can bus concepts as an electronic hobbyist, I never really put much thought into the network segregation to improve reliability. I'm also a bit of a hobby roboticist, and now, I'm more comfortable with both troubleshooting automotive problems, AND I can re-work some of my past designs for robotic networks to eliminate the "house of cards" reliability issues you mentioned!

I've been studying diagnostics on youtube for a while and felt like i got nowhere. just watching these 3 videos i've progressed. Great job .

They brought this Subaru to you because you are an ACE automotive electrical technician 👍🙂 MANY THANKS for sharing your knowledge . No doubt - If one wishes to repair todays modern vehicles - they must learn and understand what the information you are freely demonstrating / teaching in this video ✌️✌️✌️

Amazing group of videos. I am blown away at the teacher and how he explains things. Man, I will be saving these for later watching and to send to other junior technicians. Also, lol that Suby was sssoooooo clean hahahaha. Man if every vehicle we had to work with was this clean and what not, everyone would be a tech.

Thank you Ryan for all the work and effort you put into this series. I know I need to review the first two again to put it all together, but this helped to understand the "How to"s " when diagnosing communication problems.

Excellent three parts series Ryan! A lot to learn. Some mistakes I did in the past I think won't happened again after this series! Thanks for sharing your knowledge, Ryan!

very good video,especially connecting a extern resistor in at the end is epic.didn't came up in my head before.

Thank i fully understand your class. This is one of the best can bus video that I have ever watch great video

Sir Very excited to watch this video.i dont want to miss any video.

Thank you so much for the step by step instructions and for showing what not to do as well. I have seen many videos that go through this but yours lays the foundation for why in a way that doesn't "Over-Tech" some of us weekend techs whose eyes glaze over during the phd lever stuff. As a industrial maintenance tech I work with Profibus but since I am not an electrical tech I appreciate these videos that help demystify the black art of communication. I would love to see more cars like these taken through and fixed and look forward to seeing more of your video.

I Subscribed a few years ago and these video series are over the top. Keep them coming much appreciated.

Great video, very informative. A couple of notes however, at 40:54 and 42:05 you were referring an open circuit as “zero” resistance when it’s actually infinite resistance (open line). I see this all the time when I’m teaching my electrical courses. Thanks for the video! I learned many things about these networks! 👍🏻

Great video series Ryan. One of the best network tutorials I have come across. Hope to see more like this from you!

Excellent culmination of all the information and wisdom you'd shared in Part 1 & 2. I feel like I learned 15 years of information in 1 hour. Thanks!!!

Very good videos man..thanks a lot....I'm an electrician and now I have a better picture how cars work.

As an Auto Diagnostic Technician am very much delighted with your wonderful lecture on this this topic which is center of vehicle electrical diagnosis. Congratulation parting deeper CAM Bus knowledge.

Thanks for an excellent video series explaining the simple yet complex CANbus network system that run our cars. Great seeing someone step by step breakdown the wiring and network topology of connector found all over these vehicles, and going after a connector and skipping it because it's too deep in the console. Don't shorten the video just because it's not going to workout. Only take apart what you need too when you need too!

🙏🙏just fantastic I’m 69 & been found CAN a long time This is the explanation I’ve always wanted. I’d ask product instructors & be told by them honest enough to be honest ! (sorry I honestly don’t know the manufactures don’t tell us) I’ve even witnessed product instructors say ! You can only throw parts at it until it works 🙇‍♂️ I’ve been told by customers ! They fitted 3x Parts until it was fixed but charged for all 3x parts due to cost of removing them & Now the warranty bag is broken, we can’t re sell it 🤷‍♂️ Many thanks 🙏🙏

Ni darasa zuri,nimependa ufundishaji wako tangu sehemu ya kwanza ya darasa hili hadi sehemu hii ya tatu,wewe ni mwalimu mzuri na kiukweli nimeelewa vizuri.... Ahsante sana kwa darasa hili na MUNGU akubariki

so great!!! thank you for taking time and give away all these knowledge, God bless you

I appreciate your time. I have watched all 3 videos and I have learned a lot, thanks.

Excellent series 👏 Would love to see more beginning to end diags.

I have learned from your video. Now I have a better idea what to do to find out why my memory seat on my 2012 Honda Accord is not saving the memory and running the battery down in a couple days parked. Keep up the good work.

Great job thanks for sharing your experience

fantastic class...im glad i stumbled across this, completely by accident too, but i watched all 3 videos. some of these CAN bus classes can go way beyond the scope of what a technician needs to know to successfully diagnose a CAN issue, but every bit of info in this series is relevant. well done

Can't wait for this tutorial once again. Thank you From Nick Ayivor from London England UK ⏰️ 20:59pm Good Evening everyone

Great, my class thanks you from down under

Sir, I want to thank you for your dedication and passion to perform these types of educational videos you are providing us with. I am an educator as well, and your material is going to help many young adults, who are in the process of recovery from past bad choices, and today they are looking for an importunity in my nonprofit, so they can better their future. Thank you Sir again, and have a blessed day.

Im a field engineer recently forced out of avionics career reinventing my self as a Marine intrumentation fiekd engineer. These systems are now CAN BUSS. Great video...and great view inti all screen displays. So is the ECM openable for resistir repair or is it sent back as a core return for factory repair? Last guestion is a source for the test lead adapter kit. Wonderful tutorial!

That was GREAT. Thank you. I am trying to solve an intermittent communication issue on a single CAN bus and this series is a great help for my understanding. Thanks again !

I watched all 3 videos and im gon a rewatch them so much knowledge bro

Thank you for your mentorship and efforts in teaching. You are doing an incredible service.

Honestly excellent. Easy to understand even funny at times from part one till three. lol. Thank you sir.

Thank you for a great explanation of the can bus. I am sure you are educating a great number of technicians.

As a computer programmer looking to understand CAN on EVs it was very helpful. Thx

Awesome, methodical explanation. I am a computer and electronics tech, and this is what proper troubleshooting is in modern day electronic s. Very easy to listen to and follow. Keep up good work..

Another great video. Concise and no darn music playing in the background. Thank you!

Awesome , thanks so much, definitely learned a lot and feel so much more comfortable and confident approaching CAN problem issues. Keep up the great work Bryan !!!

Champ ,this is better than the original Star wars trilogy you are showing the real force..,

Hey Ryan, thanks for all your hard work putting this mini series together. You break it down so well and made all the information easily digestible. Your approach will be the one I use next time I have to diagnose a vehicle CAN issue at work. Cheers!

I'm learning a ton! I'm a hobbyist thinning out a body harness for my LS swapped F100

Great series on can bus network. I hope you can do an in depth one on K line as well. Great explanation and details

Ryan...gre8 job explaining this everyday more confusing subjet....have seen your third episode so many times.I I can almost quote word for word. People already come to mi for solutions to their electrical problems and these series have help me understand Way more than I knew before...thanks again .....subscribed.

Excellent video! Best I’ve watched on communications. I would have liked to have seen you scope the can line at one of those junctions to show what the wave form looks like when missing a terminating resistor. Then a comparison to the good wave form when you added in your own resistor. I’ve never been so excited to have Comm. Issues in my whole career! Haha

I really liked this explanation of the CAN bus network. no comments, it was wonderful. I really appreciate it

I am halfway through the video when I write this. My main gripe about testing networks is, sometimes the modules are BURIED in spots where you have to remove a lot of stuff. And that presents 2 problems : 1- You have to adjust your diagnosis time to account for gaining access to the modules to test. 2 - You have so much stuff removed that now you can't hook up to the circuits and roadtest the vehicle. Great video series though!

Excellent tutorial and demonstrations. Thanks from Darwin Australia

great job, there is no word to say about importance of this series

bro i just watched this video , and i must say it was very informative , your skills in teaching is excellent , thankyou and i look forward for more videos in electrical troubleshooting .

Excellent presentation and very helpfull

Ryan, your videos are outstanding! Your teaching approach is excellent, you provide great information in a very humble way. Looking forward to see more troubleshooting videos. Thanks Dan

Bloody awesome. I am going to watch it all over again. And maybe even again. Best network video I have ever seen. Congrats Ryan. You are awesome and thanks to South Main Auto for steering me over here.

Excellent info! Thank you for taking time to make this series.

Am very grateful sir for your time that you took to prepare this lesson.Indeed have learnt alot on how to narrow down the entire network to individual network.My request is for you to prepare another lesson on a different vehicle.However, I was not sure on which pins on pcm did you connect the resistor. Note am currently studying automotive engineering and am trying my best to acquire knowledge.Otherwise thank you for precious time.