How To Test CAN BUS With A Multimeter [CAN Bus Resistance Check] Mechanic Mindset

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4 жыл бұрын

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This CAN Bus resistance check is very easy and simple WHEN DONE CORRECTLY. In this video we look at how to diagnose a CAN bus fault, looking at CAN high and CAN low wiring with a multimeter. We cover IN-DEPTH all the different measurements you should be taking when using resistance to check the can bus network. CAN Bus fault diagnostics can be difficult; I break it down in to easy steps to help you improve your automotive diagnostics. This is equivalent to the test I perform with Master Technicians on CAN Bus Technical Training!!
I prefer to use an oscilloscope for my CAN Bus diagnostics (PicoScope 2204A), but my Fluke meter is a good tool if used correctly. We will also see if a cheap multimeter is suitable to diagnose CAN Bus too.
Fluke & Cheap Multimeter Links…
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Video Links:
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Пікірлер: 198

@highsierra21 10 ай бұрын

I cannot thank you enough for making this video! After a completely dead instrument cluster, I used the information in your videos to narrow my problem down to the instrument cluster itself and ultimately, aged solder joints inside my instrument cluster. A little heat from a soldering iron and I'm back up and running. Your videos are truly invaluable to a novice like myself. Thank you!

@MechanicMindset 10 ай бұрын

Great job, well done!

@shelbyhoneysuckle1080 2 ай бұрын

Was it a GM vehicle? Tahoe? Silverado?

@TheCarManUK Жыл бұрын

WOW!!! TALK ABOUT KNOWLEDGE. LOVE THIS.

@MechanicMindset Жыл бұрын

Mechanic Mindset Diagnostic Coach program is here! Click link: www.mechanicmindset.com/diagnostic-coach

@elit3401 Жыл бұрын

Thanks for the explanation, nice video. I work on transit buses that have an overwhelming amount of modules linked to the network. Looking for the one that is not communicating is very time-consuming. This J1939 system needs much improvement.

@arthurfricchione8119 2 жыл бұрын

Darren thanks for sharing. great video that very well explains the basic CAN BUSS system. Now to watch the rest of them Artie

@MechanicMindset 2 жыл бұрын

Glad you enjoyed it Artie! I have a. Few CAN videos in the playlist, they should all help price together CAN diagnostics. Let me know if you have any questions! Cheers

@Jern54 Жыл бұрын

Very informative, thanks for creating this content 🎉!

@sheerwillsurvival2064 2 жыл бұрын

This is the best channel for diagnosing bar none

@luv_xxx2770 3 жыл бұрын

First I want to thank you and i follow today your information about test and we found the fault (CAN wire H&L is Cut ) in engine area CAN H&L the Volts is 2.4 but we test with ohm we found 121ohm

@arthurfricchione8119 3 жыл бұрын

Wow great video and explanation. I own that style of Pico scope and will be following your videos on its usage. Thanks for sharing your knowledge and videos 👍 Artie

@MechanicMindset 3 жыл бұрын

It’s a great little tool. Great to have you on the channel! Are you pro or enthusiast?

@arthurfricchione8119 3 жыл бұрын

@@MechanicMindset I’m a retired high performance jet aircraft mechanic but a car enthusiast my whole life. Looks like a great channel 👍

@danstark462 3 жыл бұрын

Thank you Sir, that was thorough

@MechanicMindset 3 жыл бұрын

Hope it helps! Cheers

@stephanevaucelles6378 4 жыл бұрын

Thanks for the video

@MechanicMindset 4 жыл бұрын

Our pleasure!

@gajendrakhanna5729 3 жыл бұрын

Nicely explained.👍🏻

@MechanicMindset 3 жыл бұрын

Cheers, hope it helps!

@ahmedeldeeb7192 3 жыл бұрын

Thanks man very helpful

@MechanicMindset 3 жыл бұрын

Glad you found it useful! 👍

@alrifainidal 4 жыл бұрын

well done ... thank you

@MechanicMindset 4 жыл бұрын

Nidal Alrifai Glad you enjoyed it!

@coco-te1op 2 жыл бұрын

I'm 44 and just bought my first VW car with can bus. This system is new to me. It's developed a can bus fault read by Texa. I'm not one for giving up and your video has started a whole new world of learning and understanding for me. So thankyou for your time and explaining in layman's terms can bus. Thankyou.

@MechanicMindset 2 жыл бұрын

I have a few more videos on CAN too, just launched one this weekend with 5 tips for CAN diagnosis. Hope it help! Great to have you on the channel 👍

@coco-te1op 2 жыл бұрын

@@MechanicMindset Thankyou. . .

@georgedass5419 2 жыл бұрын

Very informative, am learning from you mate..... Everyday

@MechanicMindset 2 жыл бұрын

This is my most popular video, glad you enjoyed the learning!

@nickayivor8432 2 жыл бұрын

KNOWLEDGEABLE Mechanic Mindset Very helpful video tips thank you very much 👍 Mindset Mechanic From Nick Ayivor from London England UK 🇬🇧

@MechanicMindset 2 жыл бұрын

Love that you are enjoying the channel and getting through the videos! 👍

@timkaldahl Жыл бұрын

Fluke is definitely the industry standard, but any decent meter will work. Don't expect a 6 dollar meter to give precise readings. They aren't totally useless. I've tried to avoid newer vehicles, but I'm at the point where I probably need that Pico scope. Glad you have videos out so I can learn how to use it. If I can't do my own work I can't afford to drive a thousand dollar vehicle.

@rosendomedina8933 3 жыл бұрын

Thank You !!!

@MechanicMindset 3 жыл бұрын

You're welcome!

@carlosvaladez2186 Жыл бұрын

Thank you

@Solairethedarksoul 3 жыл бұрын

Good stuff let’s me know I’m on the right track

@MechanicMindset 3 жыл бұрын

Glad it helped you 👍

@glynfernandez1760 11 ай бұрын

Good job sir

@locati82 2 жыл бұрын

GRACIAS!!

@naseemansari9684 2 жыл бұрын

Thanks sir

@shameerp3289 3 жыл бұрын

Bro please help me to find out, MG 6, U0101 lost communication with TCM, found HS CAN and LS CAN short to ground how find the affected area

@johnrieley1404 3 жыл бұрын

Thanks so much for excellent teaching. Only quibble I have is at end when you are doing resistance checking, You said if signal line is shorted to positive (battery volts), you get a result, which you did not show. If you have 12V on signal line you should not test with meter resistance scale, which may damage meter. Only test resistance on un-powered lines of any sort.

@MechanicMindset 3 жыл бұрын

John Rieley Gald you enjoyed the video, thanks for the feedback 👍. Re. Resistance check; don’t forget that I disconnected the battery. Although, I have not tried measuring resistance of a live wire before. Would there still be an issue considering there was no potential difference or current flowing? Might have a play!

@johnrieley1404 3 жыл бұрын

@@MechanicMindset You are right, if no power or capacitor somewhere ready to spill out stored power then resistance check is OK. If power in line do not do resistance check with meter. See www.fluke.com/en-us/learn/best-practices/test-tools-basics/digital-multimeters/how-to-measure-resistance

@MechanicMindset 3 жыл бұрын

John Rieley Thanks for sharing!

@sollykhan2385 2 жыл бұрын

@@johnrieley1404 or use a clamp on meter on a circuit that you expect or unsure of that is somehow powered up ? or even an old style analogue amp meter in series, if the wires can be detached ? to be sure that NO live current is in play 🤔

@TheCarManUK Жыл бұрын

I have a question. Will a bad BMW M47 E90 glow plug control module give a non start and cutting out that's the only code showing with crankshaft position sensor code but the crankshaft position sensor was changed twice to be safe but still only starts when it wants to but never last more than 20 min before cutting out. What would you say to look at first ?

@MichelMarceau-dj5ef Жыл бұрын

Hi, Your video is excellent. You forgot to mention if CAN HI or CAN LO is short to groung, you will still be measuring 60 ohms. Only if you messure CAN HI or CAN LO to ground then you'll know there is a short to ground. Of course this will not be the same when you'll be measuring the voltage, you'll know right away there is a problem....thanks

@MechanicMindset Жыл бұрын

Ah yes for sure, thanks for the input!

@Mac-mu9cs Жыл бұрын

Do you have recommendation for a entry level DMM

@luv_xxx2770 3 жыл бұрын

thanks for replay i have bmw f30 fule ecu with ista red the fault is no communication i see you in video you test ohm and volt

@fernandomoran5979 2 жыл бұрын

Grasias

@petrfort4770 2 жыл бұрын

Hi. I am very excited about your video tutorial. I have a question, can I check the status of the bus in this way, for example KOMBI and DDE units? Or can only control units on the same channel be controlled in this way? Can you explain the difference between CAN and D-CAN and K-CAN? Is K-CAN used to read from the OBD socket and to encode units?

@MechanicMindset 2 жыл бұрын

Hi, this video might help with some more insights kzfaq.info/get/bejne/oZ6SfciYu97Tj5c.html Thanks!

@josht4901 4 жыл бұрын

I’m a 3rd year Bmw apprentice thank you mate

@MechanicMindset 4 жыл бұрын

Josh T Awesome, I did a BMW apprenticeship too! Great programme, which country?

@shoortey1338 2 жыл бұрын

Got a complicated problem with one of our machines using DeviceNet. Im kinda new to this but what happens is that we have several nodes in the machine including a staübli 6axis robot. For some reason when the (deadman's switch) or servo motors recieve power it knocks all of the nodes off like they are loosing connection. If we exclude the robot in the equation the nodes doesnt fault. Even with an external power supply to the robots modules this happens. Does anyone have any idea what to look for here? Have tested all the other nodes as well but works aslong as the robot doesnt recieve power.

@hiepnguyen-ee4bj 2 жыл бұрын

Great video. What resistance reading if I have an open circuit (cut or broken wire)in either CAN-H or CAN L.? While back probing at the modules.

@MechanicMindset 2 жыл бұрын

Cheers! It depends on which modules you are checking and where the break is (as per video) 👍

@eliasvillegas4867 11 ай бұрын

120ohms +/-

@samsungworld8274 11 ай бұрын

I've got a similar issue. The diagnostic connector Can hi can lo. When measuring resistance it shows zero. What i should check?

@ap-lw8725 2 жыл бұрын

Gut erklärt

@MechanicMindset 2 жыл бұрын

Thanks!

@LGaragem 5 ай бұрын

I'm having a bit of trouble with a Peugeot 407, most specifically ABS and Electric power steering, they just can't seem to connect on OBD. All other modules seem fine. I started doing these CAN resistance checks between the wiring. Something I found strange was that probing between CAN-L and CAN-H shows 120Ω with the modules disconnected. However, If i probe CAN-H on the ABS wiring with CAN-L on the Electric power steering wiring (or vice-versa), it shows 0Ω (short). Is there something shorting my CAN lines or is this actually normal? Thanks!

@mohammad45h 3 жыл бұрын

سلام و درضمن از خدای مهربان بهترین ها را برایتان ارزومندم هزاران 👍.....

@TheBest-rg8sq Жыл бұрын

Please I have ON 2 in ignition doesn’t give 12 v positive?

@gen2ux 4 жыл бұрын

Really great video. Any plans to do detailed videos on Flexray networks?

@MechanicMindset 4 жыл бұрын

Tom Cannon Yeah, as soon as I get a car with it fitted. Hopefully soon! Thanks for watching!

@gen2ux 4 жыл бұрын

Might I suggest a Volvo SPA platform. Ethernet OBD gateway and flexray redundancy (normal I know but interesting)

@MechanicMindset 4 жыл бұрын

Tom Cannon my friend has a 4 series BMW which is similar I think. They are all going this way now (it’s all off the shelf nowadays)

@callum2793 2 жыл бұрын

hi, I’m new to canbus albeit worked in garage since 2011… I’ve ordered an oscilloscope as it’s becoming more and more required, love your videos they’re great! And very informative. I also have a quick question, I have Vw transporter that has canbus faults. I’ve tested the resistance using a multimeter and that all tested out ok at all modules on the network, I then checked the voltages on Can hi and can lo, all was perfectly fine except for CAN LO at the ECU, I was getting 12v. I would’ve expected there to be 12v across the entire can lo network, or is that not how it works? Thanks

@MechanicMindset 2 жыл бұрын

Hi, sorry, how did you get on with this? If you can communicate with all the modules on the scan tool, CAN is probably ok. What did you find? Which CAN network were you testing? (i.e. Powertrain or Convenience?)

@Sean-zc3iv 2 ай бұрын

How do I test can bus on 2005 tahoe that only has 4 wire connections in the obd2 port. So confused

@luv_xxx2770 3 жыл бұрын

boss today we clean car from inside the company used sum water to clean after finish i test car i found many device have fault but working is k-can fault how to start for test

@richardostrowski6420 4 жыл бұрын

I attach my break-out-box to the DLC. I can now either hookup my DMM or my Scope as needed.

@MechanicMindset 4 жыл бұрын

Richard Ostrowski Hi, I love them flashing BoBs! Unfortunately they are becoming obsolete. If you have a car where all the networks can be accessed at the DLC/OBD port, they are great. On a lot of modern cars now, all you can get at the DLC is Diagnostic CAN, a direct link to the Gateway. In fact the latest cars this is changing to Ethernet! Also if identify a fault, we will still have to go on a mission around the car to find the problem. More on CAN coming up! Thanks 👍

@karuchvz9305 3 жыл бұрын

@@MechanicMindset you right when you have a gateway it gets a little bit tricky to diagnostic the network but if you understand how the system works you should not have any issue to diagnose the network.

@rizzygeorge 5 ай бұрын

hi...i have some problem with CAN...car îs an Audi a6 c6 year 2010...i have no comunicațional with CAN and generator and batery module .....eror j533....have any idea were to look?thank you🍻

@Spikev01 2 жыл бұрын

I really enjoy your videos and am considering to join your online. Feedback for this video is that the background music is distracting and a little over powering.

@MechanicMindset 2 жыл бұрын

I think you’ll enjoy the training, we are announcing more opportunities this month! Thanks for the feedback, this was one of my earliest videos, I didn’t do the music again 😅

@gregbevan958 3 жыл бұрын

Hi Thanks for the great videos I have a question I hope you can help me with I have no communication with my scanner so I did test between 6 and 14 and have a reading of 120ohms When I disconnect abs it reads 60ohms Does this mean abs is at fault? Thanks Greg

@MechanicMindset 3 жыл бұрын

Hmmm, it should be the other way around. 60 ohm all connected and 120 with ABS disconnected. I am trying to think of a scenario where the reading you obtained would be seen

@fixitman2174 Жыл бұрын

@@MechanicMindset There is no scenario where that can happen. It is impossible to reduce resistance by removing part of a CAN circuit.

@kinanhigh2317 Жыл бұрын

Thanks for your video, i have a problem with nissan , after i disconnected the battery i connected the odometer to the 6 and 14 pins in obd, i had 120 a ) reading , then i disconnected the PCM i got 60 a ) reading , do i have problem in the PCM ?

@MechanicMindset Жыл бұрын

Start with this video… kzfaq.info/get/bejne/oZ6SfciYu97Tj5c.html

@bbmd2200 3 жыл бұрын

I am always asking myself this question: What is the point of checking both resistance and voltage? Could you please explain?

@MechanicMindset 3 жыл бұрын

BB MD In my opinion, the resistance check doesn’t tell the complete story (as demonstrated here). You could have an open circuit and still read ~60ohm. Oscilloscope voltage is the best way, but measuring voltage with a meter will tell you more than this resistance check. See pinned comment for link, also got some videos on analysing CAN scope waveforms. Hope that helps, happy to help if you have any more questions 👍

@adejones7232 3 жыл бұрын

Hi mate I'm having a fault with volovo v70 ,from abs pump to lateral accelerometer sensor signal fault ,power and earth are there but can bus is reading 12.5 ohms ?

@MechanicMindset 3 жыл бұрын

If battery is disconnected, sounds like a resistive short circuit. Try disconnecting modules until it changes

@skibumwannabe5492 2 жыл бұрын

Hello I’ve got an E70 X5. With kcan faults stored. The voltage is 10.37v across can H and can L. 0v can L to ground and 11.06v can H to ground any ideas?

@MechanicMindset 2 жыл бұрын

Difficult to say without being there, what’s the scope show?

@alitehrani3415 3 жыл бұрын

Great videos Have couple of questions This car I have problem with has total resistance of 47ohm The 120 ohm that is in instrument cluster reads 97 ohms ,do you think instrument cluster is bad?

@MechanicMindset 3 жыл бұрын

Hi, if you have a CAN bus problem, does it go away when you disconnect the instrument cluster?

@alitehrani3415 3 жыл бұрын

Hi It is a 2007 Rangerover and instrument cluster seems to be a Gateway module so can not disconnect and start ,with you experience is it normall for 120ohm terminal resistor be 96 ohm? also when measuring it and leave the ohmmeter connected it varies drops from 99 to 96ohm Thanks for your reply

@MechanicMindset 3 жыл бұрын

@@alitehrani3415 Hi, I’ve not seen one measure 96 before. Are you definitely measuring a high speed CAN line? It may be best to get the scope out of you are sure there is a network issue 👍

@amiladasanayaka998 2 жыл бұрын

Hollo sir i need your help me .what is the Isuzu 6wg1 foult code u0073

@sachaDS0 Ай бұрын

It's weird on my car (Kia picanto I wouldn't get any reading (0L) until I have the battery plugged in. How is that so ?

@MechanicMindset Ай бұрын

Depends on which type of CAN it is. This only works for High Speed CAN 👍

@vicky-nc3to Жыл бұрын

I learned, 1. Resistance measurement is not enough to check CAN system 2. I can check short to ground/ power via multimeter 3. Typical resistance of a module in CAN can be in thousand ohm , if they do not have terminating resistance right ? 4. There are many types of different CAN system in Audi/ Porsche , e.g. power train CAN, crash CAN, infotainment CAN, Chassis CAN.. does it mean that each of these CAN has separate 2 120 ohm resistor? Thankyou for the upload.🎉🎉🎉

@MechanicMindset Жыл бұрын

Yes, yes and yes. 4. High speed and medium speed CAN networks have the terminating resistors. So yes, each individual network will have them. You won’t find them on low speed CAN 👍

@vicky-nc3to Жыл бұрын

@@MechanicMindset thankyou for this great upload

@alwayslearning6355 2 жыл бұрын

Is it correct to say that if one of the resistors is open, the CAN BUS will be down? Can you have good CAN BUS resistance and bad CAN BUS voltage (2.5 v on CAN HI and CAN LOW in idle state)

@MechanicMindset 2 жыл бұрын

Good question, from memory, CAN bus still works without resistors (ie that module disconnected). Will add it to my video list 👍

@rafaelordonio1102 2 жыл бұрын

Do I need to disconnect the battery first before test obd fort to test resistance?

@MechanicMindset 2 жыл бұрын

Yes, or it needs to be in sleep mode. I usually disconnect battery

@fatahfadhel8830 Ай бұрын

Can i read resistance inside engine Control module by pin for can high and low And what give me ohm if can that

@MechanicMindset Ай бұрын

If it has the terminating resistor, yes. 120 Ohm 👍

@lizandroalba8767 2 ай бұрын

Can you explain how it comes at ASE test

@MechanicMindset 2 ай бұрын

Hi, can you expand the question please?

@colinreid7305 3 жыл бұрын

Have you done any testing on flex ray

@MechanicMindset 3 жыл бұрын

I have but not got a video. We used to cover it on the Audi Master Tech assessment 👍. It’s on my list!

@luv_xxx2770 3 жыл бұрын

1-i will test ecu with voltmeter and Ignition On (dc volt ) 1cable to ground other with CAN H and CAN L shall 2.4 and 2.6v if same the can ok 2-with battery (-) remove i will test ecu the cable for voltmeter 1 in can l 1in can H with ohm test the shall 60 Ohm

@MechanicMindset 3 жыл бұрын

Also check that the fuel ECU has power and ground 👍

@sandymejia1120 3 жыл бұрын

I have 120 ohm and the female plug going to my gateway module and the gateway have 120 ohm too but whent check my obd2 only have 120 no 60 ohm

@MechanicMindset 2 жыл бұрын

OK, was everything connected?

@kaosaepharn4326 2 жыл бұрын

People ask why check both voltage and resistance? I work on Teslas which have 4(2 60 ohms, 2 120hms) terminal resistances, 2 in the modules and 1 in each of the drive units, with 10+ modules in each Can circuit. By checking the resistance, and if one of those terminals happens to be bad, I’ve basically narrowed it down to just 2 possible bad components, not 4. See how much time I saved in diagnosing than to just blindly check every component? It doesn’t always work out that way but it’s one of the very first steps I take when diagnosing high speed can bus. If the resistances are good then I’ll move on to checking the voltages.

@MechanicMindset 2 жыл бұрын

Great process, I’d do the same 👍

@mattharvey8712 Жыл бұрын

Bravo........in my truck.....you unplug the resistor and trigger engine light codes flasher.......what do u think.....no obd2...no plug....cheers

@MechanicMindset Жыл бұрын

Sorry I’m not familiar with the set up on your truck, or how the network is connected. Is it definitely CAN Bus?

@ichbinbaghdady2418 4 жыл бұрын

nice dude keep it up

@MechanicMindset 4 жыл бұрын

AnAs faris Thank you! More like this coming soon...

@dazzadaz4730 3 жыл бұрын

Love your videos mate, they are very informative. I have a question for you if you could help me out please. When measuring the resistance between CAN H & L pins to ground on individual modules should the resistance be M ohms to O/L or is K ohms acceptable? I have CAN bus codes coming up on my scan tool on a few modules & went crazy stripping the car down trying to find the fault. All the modules but one are reading M ohms or O/L, with one that I think is dodgy reads 135 K ohms on L to GND & 110 Kohms on H to GND. Do you think this would be the issue thats causing my CAN system to fault out? TIA from Australia

@MechanicMindset 3 жыл бұрын

Hi, glad you are enjoying the channel. Testing the CAN line of the module to ground isn’t a test I usually do, unless there is a short to ground. There are more resistors which form part of the electronics for the module, which is what you are measuring. It also depends if you are look g at high speed or low speed CAN as the terminating resistors are connected in different ways... It depends on what codes you have got or which modules are not communicating. What symptoms are you experiencing. Is it an intermittent fault. I would try to capture the problem with a scope to identify what the issue is. Also remember that module power supplies can cause network issues too!

@dazzadaz4730 3 жыл бұрын

@@MechanicMindset sorry for not being clear enough mate I meant if the module is unplugged from the network & testing this individual module H to GND & L to GND.

@MechanicMindset 3 жыл бұрын

@@dazzadaz4730 Yeah that’s what I assumed you meant 👍. It’s not usually a test I would do, but I would probably expect it to be a very high reading

@lloydpalmer5735 3 жыл бұрын

ive got this model car 320d ...

@1Wayfix Жыл бұрын

I got. Lost. Communication codes On ecm Tcm bcm. And traction control module. But. I got 60 homs. On my obd. Port. ? What you recommend. Tha k you.

@1Wayfix Жыл бұрын

From what i understand. Even if. I got. 60 hms. One of the modules. Can be bad. But i have to test. Every single. Module. Like. My case. Or im wrong ?

@MechanicMindset Жыл бұрын

I recommend this video kzfaq.info/get/bejne/oZ6SfciYu97Tj5c.html hope it helps!

@1Wayfix Жыл бұрын

@@MechanicMindset thank you. I watched already

@quentinboswell7747 2 жыл бұрын

Can a bad battery (low voltage) affect CAN BUS??

@MechanicMindset 2 жыл бұрын

Potentially yes, although I think the modules will cut out before CAN bus. When we get down to around 8/9 volts, modules start to shut down.

@elgroso806 2 жыл бұрын

Hello. I have a problem with a can bus. No u codes. I can communicate with all the modules but i can't get live data. As soon as I try read the live data on any module, the scanner takes me out and display a message of no communication. I have literally done everything. I don't really know what else I can do to diagnose the can bus system.

@MechanicMindset 2 жыл бұрын

What happened when you tried another scan tool?

@bobbaxter952 3 жыл бұрын

Hi,i've been on a few tech courses,can you explain about disconnecting the negative lead,i understand why you do it,but when you disconnect it should you have a memory saver connected?,say one of the ones that plug into the dlc connector?Or does it just depend on the car? I've even done one course where they stated as fact if you read 60 ohms at the dlc the circuit is good,yet they went on to cause a fault on the network yet failed to explain whilst doin this why their multimeter showed 60 ohms!! Your video is good,subscribed!

@MechanicMindset 3 жыл бұрын

So I disconnected it instead of waiting for the network to go to sleep. It it’s awake, you will get high readings. If you use a memory saver, you might still keep the network awake. Glad you enjoyed the video and hope it cleared up your questions on CAN termination resistors. Cheers!👍

@koookao 3 жыл бұрын

Hello mate, awesome video! I bricked my w169 Instrument cluster by trying to flash new Offline software using DAS. Unit not dead but need reflashing on bench. I stitched my control unit but now cannot read it saying error during initialization cause I didn't add 120ohm into my wires. So can you tell me if I add 120ohm tapped into Can-l and 120ohm tapped into Can-h lines I'm good to go? I measured resistance between both wires and it's more than 1 Mega ohm so think I'm measuring open circuit only no internal impedance in my cluster

@MechanicMindset 3 жыл бұрын

Hi, the 2 resistors should sit at the 2 furthest end of the network. Some networks do have external resistors (I.e. not in the module). If you measure 1M ohm, it sounds like there are no resistors at all. Is it definitely a high speed CAN network? Low Speed does not have these terminating resistors

@koookao 3 жыл бұрын

@@MechanicMindset thanks, yes it is 500kbitsps network baud rate and when I measured voltage between Can-l and Can-h I have 4.9V is it ok? Not sure high or low speed Can but it's an old car late 2004. Also some guy told me to try K-line but when I look pinout of my cluster only Can_e High and low as well as Can_b High and low (not sure the differences..) I tried both but didn't want to start initializing with my diag module. I used pin6 and 14 onto OBD2

@MechanicMindset 3 жыл бұрын

@@koookao Sorry, I’m not so hot on Mercs. If you ha e 4.9V it sounds like Low speed. You might have 2 networks as the kombi could be the gateway between the 2. Yes, k-line was on quite a few cars of that era, I saw it in BMWs a lot. Best try to get the network topology. They usually publish it in training materials

@koookao 3 жыл бұрын

@@MechanicMindset no worries thanks for helping! So if low speed do I still need those resistors? I'm struggling to find wiring diagrams for w169.. how can I connect to k-line from cluster pinout? Then should I connect to pin7 k-line and pin15 l-line also on obd2 or just k-line? Signal to gnd pin5 on obd2 do you use it for k-line?

@MechanicMindset 3 жыл бұрын

@@koookao No the 2 terminating resistors aren’t on low speed. Sorry, not done any k-line for a long time, not sure!

@iyokeobinna2363 Жыл бұрын

I love ur video but it didn't show clearly the particular wire you used to measure the can high and low one

@MechanicMindset Жыл бұрын

You have to locate the CAN High and CAN Low wire, they will be twisted together

@luv_xxx2770 3 жыл бұрын

the test like this is OK and can do for each ECU

@AnythingEverythingGh Жыл бұрын

Which one transmit and which one receive Can H or L ?

@MechanicMindset Жыл бұрын

Both and both

@AnythingEverythingGh Жыл бұрын

@@MechanicMindset can l and h, tbey have continuity to Battery positive with negative battery disconnected Is that normal?

@MechanicMindset Жыл бұрын

@@AnythingEverythingGh How many ohms?

@AnythingEverythingGh Жыл бұрын

@@MechanicMindset Didnt check the ohms, checked continuity

@b4b516 3 жыл бұрын

1:20 “Blinks in the description below” ? 😂

@MechanicMindset 3 жыл бұрын

😂

@thecordero8008 3 жыл бұрын

👍🏼👍🏼

@LOST2BAGHDAD Жыл бұрын

What if you unplug both?

@MechanicMindset Жыл бұрын

Great question! You will still get network activity. The resistance value will show a high (xx kilo ohm I think); this is because the other modules also have resistors connecting CAN H & L but they are higher value than 120 Ohm. So high, they don’t affect the reading much when all connected

@LOST2BAGHDAD Жыл бұрын

I’m just have an issue, my reading is 120, when all modules are connected even when I unplugged the ECM, but when I connect my meter through the ECM the reading will be around 45 if the ECM disconnect

@LOST2BAGHDAD Жыл бұрын

And I have no idea where are the termination resistor located, it’s 2014 Ford Fusion

@MechanicMindset Жыл бұрын

@@LOST2BAGHDAD Sorry, I’m not sure where your terminating resistors are. They might not be in ECM. When you say 45: 45 Ohms or 45 kOhms?

@LOST2BAGHDAD Жыл бұрын

@@MechanicMindset do you think can you get me on what module the TERMINATING located It’s 2014 Ford Fusion, and thank you so much

@abdfoxman 3 жыл бұрын

Ok ....

@l.franco9050 4 жыл бұрын

The right way starting at the DLC

@MechanicMindset 4 жыл бұрын

So on most modern Euro vehicles, the only network you get at the DLC is Diagnostic CAN, a direct link to gateway. DLC is no good for these cars; so those flashy boxes, no good also 😕

@JD730 4 жыл бұрын

@@MechanicMindset Glad I'm a gm tech. Databus tool works great. Plug your MDI 2 into the DLC and open the databus program. I don't know much about how Eurocars are set up.

@MechanicMindset 4 жыл бұрын

Jeff So we used to have that set up and some still do. Jaguar Land Rover only recently stopped using that topology. BMW & Audi, a little longer. Audi actually have this amazing tool. It allows you to break out the whole network and even pull the plug on individual nodes, look it up 👍

@l.franco9050 4 жыл бұрын

I found a node to be M i A getting closer i can smell it...

@l.franco9050 4 жыл бұрын

Due to its related to the trans im hoping its only a chafed or shorted wire at the valve body throwing it off

@luv_xxx2770 3 жыл бұрын

the test with battery (- ) cable removed

@mohammad45h 3 жыл бұрын

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@MechanicMindset 3 жыл бұрын

Thank you for the kind comment! I am glad you are enjoying the videos. More to come soon! 👍

@luv_xxx2770 3 жыл бұрын

the test shall remove battery cable (-)

@MechanicMindset 3 жыл бұрын

Hi, yes I removed the negative

@jamesbarratt593 2 жыл бұрын

No can lo. Any pointers

@MechanicMindset 2 жыл бұрын

Low speed CAN? Or high speed

@jamesbarratt593 2 жыл бұрын

@@MechanicMindset can low on break out box was not flashing for ten seconds or more then a feint flash lasting quarter second. Back to nothing again. This whilst can hi flashing normal. Wipers not working but central locking working on Navara jeep. Other modules no comms like ecm etc etc.

@jamesbarratt593 2 жыл бұрын

@@MechanicMindset ok so the non runner Navara on the first time I went to see it was only showing through break out box activity on can hi. Every twenty seconds or so a quarter second tiny flash on can lo. Then nothing again. Today I noticed as I had cycled the ignition can lo was there today as well. Weird. Anyway through no comms with PCM and abs module and transmission etc, I'd traced the fault to the underwood power control box. When powered the relays would click and the engine would start. How the missing power on 5 fuses could be linked to no can lo the other day I do not know. Multiple scenarios for most things. That one will most probably remain unexplained.

@hmohamed2006 3 жыл бұрын

Aà

@GraemeMurphy 2 жыл бұрын

You interrogate a Can Bus network with a standard multimeter set to ohms? This was exactly how I was shown not to do it and the damage that can be done by doing so when I was trained many years ago. Stick to spanners mate and leave the electronics side of it to those of us trained to diagnose and repair the rare faults on digital lines that do occur using the correct tools for the job. Your multimeter is injecting dc bias on a digital line that is switching between logic 0 & logic 1. That has the potential to create permanent damage to a customers vehicle and no doubt when it does you will not be paying for it, the customer will.

@MechanicMindset 2 жыл бұрын

Hi Graeme, interesting view. I’ve never heard this before. It is admittedly not my favourite way to diagnose CAN (I prefer scope - see my other videos), but literally every OEM course I have delivered, written or sat in on mentions this. A Google will show how common this test is. CAN bus is actually very resilient. See my videos where I short it directly to positive while it’s connected and running. I have done this for years when delivering my network diagnostics classes. Electrical engineers sign off the training I develop at the big oem manufacturer I work for and this has never come up. Happy to go through it with you 👍

@clueless6559 2 жыл бұрын

To be accurate a lot of mechanics hardly if at all understand can bus or networks of any kind , they cant use a scope and even a multimeter is not used properly , and i am not talking diy mechanics i am talking level three ,

@MechanicMindset 2 жыл бұрын

You’re quite right; it’s my mission to make it easy! There are more CAN videos, I think my latest spells it out the best in the shortest time 😁 5 Tips For CAN Bus Diagnostics | Mechanic Mindset kzfaq.info/get/bejne/oZ6SfciYu97Tj5c.html

@clueless6559 2 жыл бұрын

@@MechanicMindset Yes your doing a good job with quick videos not going too deep with what your trying to put across, it took me a lot of effort to begin to really understand network diagnostics and i really wanted to even working in the trade..

@aussiegruber86 3 ай бұрын

The difference with expensive vs cheap meters does not matter until you are working on mains voltages and other similar circuits. Never use a cheaper meters on mains circuits.