CAN 101

will this test work on any vehicle and thanks for the great video

Have come across you’re channel from you visiting the boys in NY. I am Up in Canada and love how this RUclips brings all people like us gear heads together 👍🏻

Great video! I always recommend my techs to hook up our scope on good working vehicles to familiarize our self’s with healthy wave forms to allow us identity issues when the fun jobs come in. Thanks

The best video yet. No "BS" like the scam mechanics, they don't want you to know this, so they lead you down a rabbit hole, low life's. Especially the dealerships, and those who sale those shorted out ECMs. You are a hero to many!!!

What a brilliant video! I've always been a bit scared of auto electrics, but I feel much more confident. Great presentation skills, keeping the subject accessible. New subscriber. Thanks

Birds chirping with a Snapon DVM and Bosch oscilloscope and a Pico breakout box... Man that is heaven👍👍

Hi Steve
An excellent demonstration - clear & concise.
A similar demonstration for the K-line would be much appreciated.

You did a great job on reading CAN signals!!! Been watching other videos not making much sense. You should be an instructor!!! You made very simple to understand.

From Orlando. Thinking about getting a Pico for personal use on my diesel truck and wife's suv. I think that you did a great job of explaining the what, and why. I really appreciate your time and efforts. Best wishes!

I have engine service malfunction on the dash, 2013 fiesta, came on today. No codes, runs great otherwise, so tomorrow I'm checking around. You explained CAN very good. I don't have break out box but I still can check for 60 ohms with meter and eliminate CAN system. Thank You Eddie p

Thanks! Learning all I can about CAN This video was a great help.

I've had to deal with a CAN problem with my own vehicle. I used the Pico Scope, BUT, I could have used the DMM like your video had shown. Thank you for showing that. With all the training I've had, CAN was VERY LIMITED! You're video makes it look easy.

Good on you taking the time out of your day to make informative videos. A couple of pointers tho. 6 and 14 are CAN high and CAN low because of their voltage differences and the fact that their dominant bits change in voltage the opposite way to each other. They are however both in the same speed network. There can be multiple speeds of network ( as shown in your wiring diagram) Referring to the diagram, i would suspect that was one data link connector but it was split showing two different networks on 2 different pairs of pins 9+17 & 3+11. Also some manufacturers such as psa use wire numbering instead of colours. So all the CAN wires in one network will be 9001 & 9002 for instance instead of blue & red or in the case of many VAG vehicles orange with brown tracer and orange with black trader. The interference in the trade wouldn't be because it is bluetooth and is normal in most instances. Completely clean switching is very difficult to achieve.
Enjoyed watching. Thank you.

The fact that while measuring resistance of the network , shorting it to power or ground (earth) didn’t change the readings… I guess this proves that simply measuring the resistance of the network is only part of the diagnostic procedure… I need more training in this .. great video sir 👍

Thanks for your time, this helps out alot starting to see more problems with these systems.

Thanks. You have explained perfectly for me. I don’t have a scope so I was really interested in the dmm results.

Thanks Steve, Very informative, I learned heaps from this one short video...You're Awesome.🤗👍🇦🇺

Thanks for making this lesson simple I can now understand can keep posting videos and keep everything simple

Great professional video on explaining CAN BUS diagnostic. You must be so busy that you may not have time to respond but I have a question.
My 07 Infiniti M35 won't start. After a can diagnostic, it shows low to no communication between the modules.
The CAN Diag result specifies: open circuit on the CAN L of the DLC branch line but sometimes it says short circuit instead of open circuit too so im confused.
Not sure if the modules entered fail safe mode due to that or if they are all fried.
The wiring of the car is big and hidden by things that dont allow to test directly at the CAN L wire.
Question 1: can I trust this result?
Can a bad ground trigger this diagnostic?
Can a lose battery ground cause this?
Your info says 60ohm at pin 6 and 14 if all modules are connected but 120ohm if a module is disconnected and you said if all module connected but still does not read 60ohms then there must be an open / short circuit (hope i got this right)
Question 3: is this info specific to the car you are working on or is it general to all cars?
Question 2: I have access to all the modules on my CAN except the TCM that is inside the transmission.
Question: Any insight on how I should go about this?
Your input will be very much appreciated.
Thank you

This is really a great video. I've never seen a video truly explain so clearly how to test and understand the CAN network. Hope you put out more videos on the topic. Can you explain the terminating resistor functions? Here them mentioned but never explained. Great video. Artie 👍

Best can video I have seen for easy understanding, thanks

super cool to see these different scenarios on the scope ..... meter work around also great .... thank you !

I like how you manufacture the faults to definitely show what happens. Nice approach.

Bloody enjoyed it,for years I have avoided electronic repairs,came across Eric’s channel,then yours,and guess what,after all these years of saying no ,to compcated ,I’m am interested,enjoying,don’t jump to conclusions,prove the fault,9 out of 10 it’s a wire ,big big thanks,keep it up,ps I bought a fiat basket case,so I could put it back together,to diagnose the 1st problem, and I have green crusty on back fuse11.many many thanks,

Excellent Steve. Very well explained. I do a lot of Mobile diagnostic work but occassionally I get a canbus issue which causes me problems. Now, thanks to you, PROBLEMS SOLVED !! :-) Keep up the good work. :-)

Steve, great video, Bosch invented can so nice to see Bosch scope!!

Great demonstration Steve with clear and concise explanation. Also good to see the correlation between the DVOM and scope. Keep up the good work! 😀👍

Say the PCM is shorted. Will it read 120ohm as if the pcm or bcm was unplugged?
Also is a labscope required to check these or just to confirm by display the mirroring effect of can H and L

Great introduction to the intricacies of the Can system which can get tricky for most people.

Yes two CAN videos today. Good video. Been waiting for CAN VIDEO so long. Thank you

Jim Nicholson
Good video the breakout box makes it very organized. If I am careful, I can take notes on the measurements on paper and find my link error on 2003 Hyundai Santa Fe.

I'm chasing a U0073 code & vehicle drives perfectly, only noticeable issue is EGR & EVAP monitors refusing to "pass". I'm getting 60 ohms across CAN HI & CAN LO. However, I'm getting 2.2v on CAN LO & zero voltage on CAN HI! Breakout box shows the light flickering constantly on CAN Lo but the light for CAN HI is intermittent. I'm stumped!

Thanks for this great video. I see people troubleshooting the CAN network but never a good working system and starting from A to Z.

Great vid that 👍 Unsure how it’s taken me so long to come across it!

Excellent informative video, thanks for taking the time ;-)

Thanks, its a big thumbs up from me. Great video and set up.Still getting to know CAN. This helps a lot

Thanks for teaching sir it's very helpful keep it up may GOD bless you

SIMPLY DIAGNOSTICS, how do you upgrade from a CAN bus 2.0A or 2.0B to a CAN FD? what scanning tool do you use to verify and test each CAN module? When you disconnect a Module this is an OPEN condition, how else can you create an OPEN module circuit?

Please help!
How can I solve this car problem? Recently, a client called me to fix his 2000 Toyota Avalon car that cranked but wasn't starting.
From the onset, the car experienced several mechanical, as well as, electrical issues. Some of those problems were:-
(1) Engine Oil consumption;
(2) Engine misfire;
(3) Engine rattling;
(4) Intermittent hard starting after shutdown;
(5) Hard to engage in drive, except engine is hot; etc.
Hence, he took the car to a garage inorder to rectify the excessive Engine oil consumption and other car problems highlighted above. Consequently, the car problems exacerbated after engine rebuild by the engineer!
The car owner wasn't satisfied with his repairs because it seems the engineer was deceitful. Although the car started after the rebuild, the problems still persisted. Valves weren't grinded after engine overhaul, engine still misfired at idle and when accelerating, etc.
The engineer whose garage the car is presently being parked, requested for another engine overhau/ rebuildl. After engine rebuild the car started, the oil was mixed with water; the engine was still misfiring, rattling, etc. It was obvious, that he didn't use durable parts to do his work.
Hence, the car owner moved the car to another garage for better repairs. The new garage suggested to the car owner that another engine rebuild is pertinent for optimal engine operation.
During my conversation with this engineer, whose garage the car is presently being parked, he told me that: "when the car was first brought in, he noticed a black smoke ( maybe he was mistaken for blue smoke, at exhaust tail at idle). When accelerating, there's a loss of power, engine bucking, popping,etc. After the rebuild, the car didn't start because the mechanic didn't unlock the car with the remote but proceeded directly to cranking the engine. In addition, the security relay wasn't actuated for starting to take place. Electrician did some wire cutting around that axis which he said was corrected to factory, opened with a remote before the car started.
Fortunately, after everything, the car started again. But there was still an intermittent misfire. What the car owner said was that, 'even when the second mechanic did engine rebuild, the car still misfired. Until he personally bypassed earth from the COP wire to the solenoids very close to the fuel injector often tightened with 10mm knot and depicted with blue and green colors on the picture. Car owner verified that the reasons for the misfire from both mechanics which still prevailed, was due to the solenoid valve that wasn't opening. That's why when accelerating it experienced a loss of power, similar to that experienced by a faulty fuel pump.
After gear oil replacement and test driven by the second mechanic , smoke started emanating from the engine bay. Precisely, from the fan relay that the car owner connected by himself. Within few minutes, the car shutdown by itself as if fuel is finished. As he tried to restart it, the car refused to. Infact, when the ignition switch was turned to Acc/ ignition position, battery and fuel light was not displaying in the dashboard/ instrument cluster. However, during cranking battery light glew faintly and start. But when throttled, it would shutdown. Electrician verified and replaced the alternator diode with a new one. When Ignition switch was turned to Acc/ ignition position, the battery and other lights came out brightly but when cranked to start engine wouldn't start again. Sadly, it still wouldn't start.
I tried to scan for DTC codes, but my scanner wasn't communicating. I checked all fuses, power and ground at obd port, those checked ok. but my scanner isn't compatible to read CAN network. there are only 4 wires intact for the obd2 port.
Furthermore, I added fuel through the intake to the engine, no change at all. I checked for spark and injector pulse. These things weren't present. But there was power to injector with just the key at ignition or ACC and COP had 1 ground and 1 power as usual.
Electrician from that garage, who also worked on the car said that he sniffed burning smell from the ECU, however personally I didn't when I went to start the car. I don't know how certain that was. Hence, I pulled out the ECU to a laptop board engineer to test the components inside. He said: "everything looks ok and test fine, however the IC he doesn't have the right tools to proceed with the test. With the ECU removed battery connected, Engine light would come ON. with ECU connected check light still comes ON.
Before I left, I checked the MAF sensor 5 wires and noticed that 3 wires were earth instead of 2 and 1 power; no ignition current/ power was available for the remaining 2 wires.
Please, what should I do to start the car?

Yeah, I definitely need to study your videos so what do you think about that $35 osculating scope from Amazon

Great video man. You really broke it down to make it seem easy as cake. Definitely took a lot of mystery out of CAN diagnosis.

Holy crap this has to be by far the best networking diagnosis video ever. Very very good detail in everything. Is there going to be more. I'm hooked now

great explanation. very helpful. keep up the great work amigo!

sir you have a great video, pls continue what you're doing. have a great day.

What is hapend if im not have any measurement for can bus and voltage is up to 4v

Great video you made it so simple more me to understand. Hope you will continue with the rest of the communication networks.

I just saw you on WUW with Eric O on the South Main Auto Channel. Very entertaining and fun. First time on your channel. Good Video and Camera work. Good instruction and tips on CAN Lines. As Arnold would say....."I'll be back!"

This explanation is good on all test procedure or it give short circuit or faulty Ecm.

Cheers Steve for excellent can training, I now name this day CAN SUNDAY after you and diagnose Dan's videos! Cheers my friend, Sandy

Simply great video! Thanks Steve

If one of the modules on the circuit(NOT the ones with the 120 Ohm resisters in)was open circuit would this cause a loss of data transmission?....Thanks Steve very informative video

Great and clear explanation in less of 30 minutes!

GREAT VIDEO , JUST CURIOUS CAN YOU HELP WITH DIAGNOSTIC QUESTIONS AND GOOD TO SEE YOUR VIDEOS EXPLAINED IN DETAIL . I HAVE A FEW QUESTIONS BUT THAT WILL BE FOR A LATER TIME IF YOU ALLOW PLEASE KEEP UP THE GOOD WORK AND THANKS SO MUCH FOR TAKING YOUR TIME TO MAKE THESE VIDEOS .

Hi Steve. I have a Volkswagen T5 2006. And have a fault on the physical network and I’m looking to get a wiring diagram so I can investigate the problem.
Do you know where I can buy one.
Great video thanks again

Another very good video from you. Definitelly very good automotive repair channel!!!
And good comment section.
Greetings from Serbia.

Nice 101! Thank you for sharing!

Thank you for the video. I was wondering if the voltage tests here would be the same on Chrysler CCD? I know the pins at the DLC would be different, I think 3 & 11, for CCD+ and CCD-. I have a 1998 Voyager, with codes P1698 & P1695, the instrument cluster does not work, and disconnecting the climate control module seems to keep the CEL out but doesn't help with the instrument cluster. I really don't grasp CCD yet, and don't have a scope. I was hoping for some direction, and also if I do have to buy a scope, could it be an inexpensive one? Ideas? Thanks. D.

Would be good to do a video on one with a fault.

a very good example of can communication. thanks, sir, great video

Hi steve this might be a tough one for ya I have a qg15 nissan almera and changed my front driver side door to the Singapore model now there are two extra wires because this door has powered side mirrors someone told me to bridge the wires but I would love to see a schematic colour code so I don't burn anything pls help

Tech channels don't get the popularity they deserve.

What is the blue box your putting the volt meter leads in?

Steve u make it easy to follow compare to other people on you tube grate tutorial keep up good work buddy u first i have subscribed too thanx

Great video Steve and nice touch with the DVOM and scope while disconnecting terminating resistor modules and short to grd & voltage. Keep the videos coming!

Great explanation in simple English

Where did you buy the obd port extension probe tester,the blue one?

Steve what a great video training tool thank you sir. keep making em!!!

do you find that pin 6 and 14 on all makes and models are the can hi and can low circuits?

Is CAN Hi 2 white wires twisted together or is it a Hi and Lo signal wire twisted together. Just a little difficult to decipher. Thanks much good video for testing 👍

Are all 120ohm resistors on bcm and pcm on all vehicles? I got a 10gmc terrain 2.4 I'm working on and pin 4&16 reads out 120ohms.

Great video , thank you very much. Where are you getting the info for the wiring diagrams ? And I would like to know, from where does a free workshop is taking the repair information for all the car brands ? For example what kind of component has the engine, or how do you change a timing chain ect. Thanks in advance 🙏.

Great video Steve! Very hot topic for a lot of technicians. Can't wait for more 😁 Thx! 👍

I enjoyed that video that demonstrated clearly, things in the real world don't always agree with what's written.

Brilliant Steve and thank you.

What is the difference between chassis ground and signal ground?

awesome i find your videos very enlightening and informative thank you

Excellent video! Please do more in this series. Thank you.

Good Job Amigo !! Thanks a Lot For Sharing

Absolutely awesome and rare info thankyou very much and many notes written down.

Well done some mysteries solved.

Excellent teaching keep up with good work :)

Excelent tutorial! Thank you!

That is one fine setup!

Great explanation thank for the time you take to share your knowledge

I’m having trouble with a vehicle would you mind giving me some tips ?

Thank you, you simplified it why do training courses make it so complicated and long , i think i get brain drained after 2 hour :(

Really good explaination. Thanks for the video.

Excellent how to video.

I have can faults can u fix merc cclass

Are you suppose to disconnect the battery before ohming the network?

What's k line and l line ?thank you

Hello, thanks for the video. Any chance of some more details on that Bosch scope - model cost etc? I'm guessing in consists of software for the computer + some kind of hardware to connect? Cheers.

How many channels is the scope you're using

You are welcome. Amigo

Next time Most-bus Wednesday?🤣🤣 Great Video Steve!

Great Video! Explained Well.

I'm was totally unfamiliar with this newer system. I couldn't resist. I had tune in. Great primer in how it works and what the actual signals look like. That breakout box is terrific. I think just about all manufacturers have switched over to the CAN bus system?

Very nice video man! Thank you for sharing this.

hey man stumbled across your video found you through watching SMA! this tutorial is awesome btw im trying to diagnose 2007 chevy equinox with all wheel drive u0073 and a p2544 codes service stabilatracs in the cluster doors locks cycling limp mode got the car home i was able to pull thoughs codes before it lost communication! checked resistance between 6 and 14 at the dlc im getting 6.25 m on the DVOM and at the abs connector ! i have no communication with high speed lan and its not crank no start. i measured resistance at the pcm i have 120 ohms, i haven't tested the other resister yet do to it living on top the clutch control module on the rear diff. out of the dlc it reads 2.5 high side and 1.8 volts low side. ive disconnected modules one at a time trying to gain communication with something and nothing i must being something wrong any help wold greatly be appreciated im really trying to learn the network side of things thats so much and merry Christmas!

Great vid some good info there clearly explained