Wow! What a great video and demonstration Dan! Not working on BMW myself I found this very interesting. So I am curious after seeing this and want to run something by you. Let's say we have a car like this come in and identify the module is unplugged and realize plugging it in creates a no com and causes the no start. We go through the basics verify +, - and com lines at the module, yet see that the module is not pulling down the whole network and we now have the suspicion that it may be an input problem and perhaps not a faulty module. At that point instead of removing inputs one at a time could we just unplug it, jump the +,- and Com lines from the connector to the module and see if com is restored and if it is then chase down a faulty input? Only reason I ask is because what if there are 30 or more inputs and we de-pin them all one at a time just to find out it is still a no com, or perhaps the rare scenario where there are 2 bad inputs? By all means not criticizing your work and I do love your approach but really would like to know your thoughts on this. BTW stayed up WAYYYYYY past my bed time watching this! You have a great way of making it very interesting to watch!! -Eric O.
Also one more thing I guess I assumed the K line stayed good with Comfort Access Module plugged in or is hat a bad assumption? I see it was tested unplugged proving wire integrity. Wait I think I have been up to long, must be with it plugged in it pulled down the whole K line right? Oyeee... I am going to bed...
South Main Auto Repair, Eric Wow you made me read a lot! Must be the longest comment ever🤣. I understand your question. This is where knowlege of the system playes a role. Let me give a simple Example. When you check a hall sensor you know what your looking for, a power/ ground and a signal. But when your doing checks and you see a ground where your expecting a power, you know something must be wrong. I measured the Lin-wires on this module and wasn't seeing what i expected. Of course you don't start out by unplugging all the wires but you can do some measurements first starting out with the wires/pins that could cause your symptoms😉. Wow i suddenly realise this must be the longest answer on a comment so Far for me, and i just woke up🤣🤣.Thanks for your comment Eric i appreciate it!👍
Hey Eric I think it would be the same result weather you use a jumper leads to re power the module and reconnect the network or jus unplug the inputs. The fact that normal functions returns and we agree at this point there is an input issue, we jus don’t know which one. So either approach would end up with the same result.
South Main Auto Repair...I guess that is a valid question, but still leaves a very important piece of information unanswered!! Not knowing the very accessory exists on the vehicle, and then not seeing a communication with that specific module, then even going as far as even checking for the operation of the accessory that is causing a problem, would lead most if not pretty much all techs to skip over this particular problem!! Even when the module was working and the offending input was unplugged, the module still didn't show a trouble code! How can you even get to the point that you would continue to inspect for a problem, when the problem doesn't even appear to be present?? I once had a friend call for advice, when his truck failed to start, and a battery replacement, and then a starter replacement, and then a starter solenoid replacement, didn't cure his problems, and the truck never would start. I suggested that his A/C compressor was bad, and he explained that it hadn't worked in years, how could that be a problem, now? It turns out the compressor locked up, years ago. Then the bearing around the pulley locked up, and the locked compressor wouldn't let the engine turn! I expect it was just experience that led me to that conclusion. Even though I had never personally experienced that problem! Did some info from your experience start you looking in the direction of a problem that didn't even appear to exist? The info about the option only existing on cars with the lines on the door handle, that's like knowing the secret ingredient in grandmas secret soup recipe!! The car won't start, and you thought "MAYBE THE DOOR HANDLE, THAT DONT APPEAR ON THE SCAN TOOL, IS BAD"! Tell us, how long did you look for this issue?? How many other paths did you try first?? How many people did you want to slap, until you figured out the problem?? If fixing this problem would have saved my life, I'd be dead!! You are a magician Dan!! Very much entertaining to watch, but even more enlightening!! I just feel smarter, watching these vids!! To quote someone pretty famous: "WELL, THERES YOUR PROBLEM RIGHT THERE, LADY"!
Super diagnosis on this car ,explaining this to the customer would be difficult. Without watching the video most people would have a hard time accepting this as the cause of a no start well done, regards Rich.
Richard Mounfield, Yes exactly, people often think you just read the codes and the scanner just tells you what's wrong with the car. In this case i can tell to go watch the Video!🤣🤣
You are a true artist. Having worked in dealerships for years and always being pushed for time and to make money for the company. year I know excuses. love the way you explain why you are following the steps you take and your diagnostic techniques.
I'm a bit late to the party with this one because I've only recently discovered your channel. Just wanted to say that I salute you for always going the extra mile and not admitting defeat. It's so refreshing in this day and age when you take your car to a garage and they simply say "Everything's showing normal. We can't find a fault." You do great videos.
A true professional with a very clear teaching style - really enjoy listening to you talk us through the problem methodically. Great to see the testing and proving of components not just parts swapping.
I had this fault in my BMW Master Technician qualification in 2010. In the Uk we have to re-qualify every 3 years or lose it. I found the fault in 20 minutes. It’s all a matter of understanding the functionality before diving in.
@ferkemall It's about understanding car manufacturers exist to sell cars and they put whistles and bells on them to attract buyers, who generally aren't car mechanics or technicians. Once one manufacturer adds something, their competitors have to follow suit. Also, a lot of modern cars don't give any trouble compared to those made 40 or 50 years ago, especially in places like the U.K. and they're a lot safer and better to drive.
Gotta love real pros. I remember having some fault in my car in 90's. I heard about older car electrician (he was actually referred with that title) in very remote place. I drove there and guy greeted me and drove car into his very small workshop. Place was filled with diagnostic tools that I very rarely had seen in any bigger workshops. I loved how the guy opened hood and looked for it for a while and told me "Hold, on this additional grounding seems to be work of mine". He looked the car plate and went to check out his files. Came back in couple of minutes and said "Yes, this car has been here before and I've indeed made additional grounding to alternator because of noise that created havoc on car's ECU". He literally explained every detail he had done and first checked that his repair is still good. It was and then he proceeded diagnosing car and was done within about 5mins of scoping. He showed me poor labda wiring he found and showed me how signals should look. Then he said that I actually have part for it and if he wants me to install it. Whole deal took I think bit less than hour and car was fixed. First shop I went and told symptoms they actually said that they're unlikely to find problem for it and that they would try to replace couple of components without warranty (kudos for them being honest). Second shop mentioned that they would find the problem, but they weren't specialized in such problems and it would likely be costly repair and told me about this car electrician. I also remember during that time that there was talk about the coming common-rail diesels and this older electrician told me that he was already doing education for them as he suspected that there weren't going to be specialist for them in a while. For sure that statement seemed to be 100% correct. This older guy had quite steep hourly wage, but because of his expertise that really glowed all over him, I would've paid even more and happily 😀
I used to work on auto training videos for aftermarket techs. They were hard work, very time consuming, and not nearly as good as these. Cannot begin to thank Dan enough for the thought, effort, and excellence of these tutorials. I intend to watch each and every one.
Hey Dan, I teach electronics to auto technicians and I'm watching your videos as my grandma watched coocking TV programs. I really enjoy them!. Really appreciate your quality work.
Hi Dan and thank you very much for your input! I'm not a mechanic but a musician but recently I found some of your videos and I'm watching them with pleasure. I like your logic and way of thinking.
Good Job Dan. I can understand the satisfaction you have after fixing the problem. Long ago I used to work on railway air condition and door system looking for electrical and electronic failure. Your work is reminding me of my past work and enjoyment i had while working on trains. .
Dan , that was very good troubleshooting to find the fault, I came across your channel by accident and you are one of the best along with,Eric O, Ivan and Keith D on Long Island. Thanks.
A very good explanation of how to break the circuit down for testing . And not to panic information time and knowledge with a lot of patience are needed Thanks for sharing.
Super great educational video. I appreciate how you show the entire process with explanation of what you are thinking and why you are doing what you are doing in all your videos.
I really, really enjoy your calm and systematic sharing of really hard core "automotive puzzles" that modern cars present these days. This one, with a door handle sensor being a culprit and "escaping" the scanning tools....well, I am only a user, no professional, but all this to my mind is over engineering with so little to benefit of and so much to be miserable with....the reason I subscribed is because I really enjoy your tone and professionalism..and used to play around my granddad when he was working on his vehicles back in 60' and 70'..👌👍
Hey Dan, thanks for this, man. Even though most of us may never get this exact same problem, the way you went about diagnosing it will help regardless. I wish I could show this to every customer that walks in and thinks a fuse or oxygen sensor is the fix for everything!
I have watched a lot of your videos and I am even more amazed by your work. Different cars, different problems all the time. Sure, sometimes there comes an odd ball to you that cannot be diagnosed after a lot of work. But it is hella amazing that you are able to find out such bizarre problem root cause like this door handle, or a ABS module wire touching an exhaust in some other video. I am hugely impressed by that. It takes a lot of hands on experience, time, a huge deal of patience, some good tools and access to the diagrams and data... Like wow. By watching all those videos, people are able to learn all kinds of interesting details. If needs come, I could use gained knowledge here on my Audi A3 8L from 2000. An outstanding job, and huge help to us all!! Thank you!! (BTW, greetings from Poland! :) )
Hello Dan! I've just now found your channel and I can only say that i am amazed of what you do and how you do it! Great videos on how a true mechanic should work on a car! I can't wait to see all of your videos! Greetings from Romania!
WOW!! You are a wizard , if I just had the electrical knowledge you have , I have been in the automotive field for several years and t always wanted to improve my electrical knowledge watching you sure does help.. Thanks so much for your videos...
Have no mechanical experience, but have watched so many of your videos after a redirect from another channel. Have found your videos interesting due to the analysis of each problem, logical approach with good communication as to why each step was followed. Thank you.
i seen something similar recently on a Benz S class, all these new electronics really can throw you in a tail spin of frustration if you dont have a way to check for canbus communication or a way to test the wires, it also goes to show even without the scope the trusty test light is still invaluable on these computers on wheels. great video and keep up the awesome content this is the kind of thing everyone needs to see when fixing modern cars
Fantastic.... if I ever have a "ghost" problem in my car that I cannot fix, I will deffinetely reach for you man, you are really good at this, and an inspiration to anyone who loves car electronics/mechanics
this was a great , educational video! It's length showed me how complicated solving , etc, the system is! Thank you Dan for the videos! They are so quite helpful and you have simplified repairing them on my terms,
Hello Dan great video! I'm a tech as well and I had the pleasure of having a issue like this on a mk7 golf with kessy, but I had the pleasure of being the first to diag it. It was the same as yours except my gti was completely dead upon arrival the ignition didn't turn on as well , couldn't even scan the car for any faults. My mk7 had kessy and push start. So with nothing telling start access to turn on terminal 15 to turn on the ignition switch I couldn't even scan the car. I looked at wiring diagrams, I manually activated terminal 15 at the relay with a jumper wire, was able to get communication and basically performed the same steps as you to find the problem.I lost my shirt on that job, but I did find the problem afterwards. A short in the comunication wiring at the drivers door module took down the whole comfort bus not.
Hi, i deal with these sorts of faults every day, i love my job its so much fun. Ive worked for myself for nearly 12 years but ive never seen or met anyone who goes as deep into diagnosis as me- except diagnoseDan. Great channel, very interesting.
Great video , I couldn’t help but notice the bloody knuckle too.....just like me. Thanks for all the tips as I’m seeing can bus problems in so many cars.👍🏻
Yep with you on that but I did witness a $4.5M loader not start for 3 days after a service, what a revelation when turned out to be washers fluid empty as last of it used in running checks then once shutdown would not start as was " a safety interlock" go figure ! Pays to think outside the box like Dan does I guess
This particular example of abonimable fault tolerance in the circuit design aside, I think it's lawyers more than anything else that is responsible for the frequency of automotive function self-terminations: "if we can't be sure it's working properly, disable the entire car to avoid liability, because nothing could possibly happen that could be considered our fault if the car is an immobile unresponsive deadweight."
Good intent I suppose as a safety. But bad bad execution. Was a dark day when engineers decided to interconnect non-vital systems to vital ones. This is why I like my 1-wire vital-to-igntion 80s VW diesel. Only catastrophic engine failure could leave me stranded. Otherwise a fairly basic tool set kept with me along with small minor extra bits like wires or the odd bolt...hell even some rope for replacing a V-belt IF it goes...& I'm good to go.
@@JUDALATION Or a Tesla. I'm even more surprised that this caused a no-start condition as a result of a dumb input which doesn't throw a code. You'd expect any failure that inhibits the car to start to have some kind of diagnostic.
You sir, are the MAN! I've just started in on a couple e39s and thought I had learned a lot about how canbus works, apparently that was not the case because you are blowing my mind! You have a new subscriber.
Honestly it makes sense to me. The car detects that someone is holding their hand on a door handle, and it won’t start. Since it’s not an automatic it cannot control gears so it must protect that person
Even if that is meant to be, the real problem is not being able to fix the problem. Shame on BMW, don't they have highly paid mechanics? My bills seems to think so.
@@josepeixoto3384 meanwhile I got a job in BMW independent service. These cars have plenty of modules and data lines that are very expensive when they break
The touch entry / KESSY on early VW Touaregs also likes to wig out. The handles are ok, but the driver transistors in the KESSY module fail. Initially it causes a battery drain because the module won’t go to sleep. Eventually they short completely and blow some internal fuses in the KESSY module. Good news is the transistors are about $6 each. Beats $$$$$ for a new module at the dealer, plus shop time to reprogram all the keys.
@@Diagnosedan More info here: www.renntech.org/forums/topic/37055-keyless-kessy-entry-problem-fixed-after-5-dollars-and-1-hour-o/ On the VW system the door handles have antennas in them too, not just touch sensors.
Hi Dan. Thanks very much for making your videos. I am a troubleshooter and have learned a lot form your videos relating to new automative electrical systems. Dan in Winnipeg Canada.
The comfort access door handles have been a problem for years I’ve only seen them cause a parasitic draw nothing as detrimental as you’re example thanks for sharing. I see a lot of these door handle issues and the way I diagnose them is with a laser thermometer hit all the handles and the one with the temp a couple of degrees warmer than the others is the culprit unplug it and check your meter chances are the draw will be isolated. If it’s hot outside I’ll pull it in my bay before I leave for the day and check them in the am. I dig your oscilloscope with the included wiring diagrams I’ll have to add that to my Christmas list thanks again keep up the good work
Diagnose Dan, perhaps you could make a video where you used an infrared thermometer to detect heat caused by faulty wiring, or component, drawing excessive current? A lot of people are not aware of this troubleshooting technique.
@@artsnow8872 I bought one of those thermometers when i saw someone use one to diagnose a miss fire on a motorbike cyl. , by measuring the down pipe temp.
DiagnoseDan Not to forget that you give the opportunity to other fellow youtubers ( that take their time to comment your videos) to learn how to use their diagnostic equipment. 😈 Sorry, could not help myself on this one. 😁
Excellent diag! I must admit half way through i would of put money on a internal fault within the module. But going after the inputs I've never seen before! Great work genuis!
Dan mentioned that a bunch of modules had been replaced during the first repair done by the shop and dealer, so that module may have already been replaced.
Excellent fault finding and rectification. Nice one Dan. So many times other ‘fingers’ get to have a go first and cause more problems. Well done once again. I really enjoyed this one. Regards Peter A. (UK)
Great video , very informative. It seems to be the case that you need to check inputs when diagnosing LIN bus systems in addition to the powers and grounds.
That is the problem with many workshops today, the electronics has gotten so advanced, they simply don't have the competence to fix the problem. Then they start to arbitrarily replace expensive components and the cost is mounting.
@@ROGUESPIRIT_ I disagree. If one changes components because of "feel" and not diagnosing problem, that simply means that technician isn't qualified for such repairs.
@@ROGUESPIRIT_ WTH? Why are you so butt hurt about that comment? Yeah I don't work with cars. I work in industry as as packaging machine mechanic, which involves some electrics. You definitely give impression that you're incompetent car electrician and swap components "blindfolded". My definition for that is poor expertise, I don't care what you happen to think 😂
Dan I’ve seen your video in the past and yesterday it saved me big time! I went to start the car and the steering symbol would come on and no ignition. After some time I remembered the video and I unplugged the CA module and wouldn’t you know it the car started right up! So in the next days I’ll troubleshoot it. Thank you 🙏🏻
I don't comment often, but when i do it's because of something untrue, or because someone does a great job! Keep it up, it's nice to see good work from trustworthy people
Ive been watching Your channel only a few days, definitely the best channel ive subscribed too for vehicle diagnostic and repair. Learing a lot on here, thanks from Ireland 🇮🇪 👍
This reminded me of a video ScannerDanner did on an Audi S5, where the high pressure fuel pumps where shutting down because of a fault with an active engine mount. What can you say...German cars! And yet, I still like them.
I guess that would be acceptable behavior if all the modules are still accessible and there's a proper fault for the problem. If they need active engine mount, they probably need that thing. I assume there would be a bumb in the hood if the mount does not work correctly...
It does not take much to make a BMW go complety whacky. Just leaving the hood open for a while makes my car display all sorts of failures in the dash as the dash wakes up while others are asleep.
So... I agree with this 100 percent. And BMWs are terrible cars. ... But I also noticed that the paint texture is slightly less smooth silky BMW on the faulty side than the working side. So I suspect this could have been either removed and replaced before or survived the crash but the impact jarred it enough that it just happened to die eventually.
Definitely a kool video Dan! I know these problems require persistent approach and tht is why you deserve a big thumbs up bro, thanks for the video and have a great day!
Joe's Auto Electric Thank's!👍. That's proberbly because the shorted wire is a Lin-communication wire. These communicate between 12 and 0 volts. So these wires are designed to be pulled to ground.😉
Well that explains a lot, I’ll have to remember that for the future! Probably will forget though, the older I get the harder it is to remember. Always interesting & wonderful videos Dan thanks!
Besides your super ability, the most important thing was that u had a good one to compare it to. I know there was a tremendous amount of work that we didn’t c due to editing and time constraints. The short to ground in the handle was enough to cause a battery drain, but not enough to blow a fuse. Their would have been a draw on that fuse/module that would not have timed out. That would have been another path to the problem. Getting Eric O. to write a paragraph is sure fire evidence that your channel will soon go thru the roof. Now if New Level comments? This is definitely a teachers teacher channel
Bill, regarding that BImmer battery drain the 1st process could have been disconnected battery neg. and reconnect with a volt meter between it. Any volts above say above .05 should indicate a short somewhere in the system. The problem is on Eurocars the computers 'sleep' for 30 minutes after the car is shut off and opening the trunk reignites the system again. On my Mercedes I get 11 volts on ALL my cars when I do that but they eventually shut off... Regardless I get lousy battery life out of these cars.
Hey Dan, you have definitely got a 'HANDLE' on this one 🙂 ye BMW's are a funny car to work on, continuous software upgrades and never ending problems!! Thank you for uploading all these great videos, they are a minefield of good information, keep up the fantastic work 😎 BLESS
Dan, another great video! Door handle. After watching, I went out to my 750li 06. Having BMW do soft door recall. With the key fob near door, put my fingers in drivers side door handle, locks unlocked without pressing button. Repeated the rear two doors and same thing, they opened. Went to passenger front door, slid fingers in handle, nothing! So my 750 is in driveway and wont start when I depress start button, like the gold car you were working on. Now I have to find where the module is that you found on the gold BMW? Figured also that I had a parasitic draw on my battery. Charge up, next day low. My car is equipped with a fridge between the back seats, when I got car back from dealer, I noticed if I went into climate and rear fridge it was locked in the on position so I couldnt turn it off(thinking this was drawing down my battery). Now, one other thing I noticed is that the steering wheel will go in and out, but not up and down. And not sure if the steering wheel locks?? PS I call this summer 'the BMW endless summer'. This car has ruined our summer vacations. The car is in such great shape, although if i don't figure it out? I will have to take a big loss and scrap it.
It's proberbly easier to disconnect the doorhandle to check if the car starts again. It has the same effect. I guess there are some video's on YT how to get the doorhandle out.
Dan do you know if the customer got a refund from the other garages for all the parts they replaced that were not faulty? If that came from the BMW dealership and they said it was fixed and all they did was unplug that module, I would be really pissed off.
@@TairnKA I agree! But, they did actually do something? Granted, it didn't fix the problem! In such a case you either contact BMW headquarters directly or your State's Consumer Affairs? BMW AG simply has to do better.
@@jamiesmith6838 Well, they apparently worked out the problematic module. Maybe someone used the word "fixed" but they didn't mean "repaired", maybe they were referring to they "fixed" the not start issue. I assume whoever unplugged it knew something was up with the module. Perhaps manager just didn't have a clue, or it was poorly communicated.
@@Cheepchipsable Anything is possible? How much does that machine cost again? Not even the BMW technicians can keep up with all the tech compounded yearly in their own cars apparently? $47k and a faulty door lock module shuts the entire car down?? I can't in all sincerity simply dismiss such a blunder like that. That comes pretty close to their sudden and inexplicably catching fire while parked?!
Good diagnosis. Had this problem on several BMW’s. It’s amazing how so many mechanics just throw parts at cars without doing the correct diagnostic procedure steps. In my experience as a BMW tech however I have found through experience sometimes with this customer complaint and no faults with a vehicle with CA (Comfort Access) it is much easier just to disconnect the door handles one by one (drivers door first as most used) and re-test from there. But you did an extremely good job of explaining step by step of what you did to prove your diagnosis 👍
It’s called expensive, over-engineered junk!!! There’s no need for a “smart detector door handle.” A mechanical door handle does the job just fine, or even better, and would NEVER short out, and disable the car like this one did.
The owner elected to buy a high end luxury car with all those computerized features in there. He probably got all excited looking at the advertising and marketing and started thinking about how much his wife or girlfriend (or both) would be impressed by all the bells and whistles. He got what he paid for.
What made you decide not to condemn the comfort module and go after inputs? Seems like most would replace the module if you had communication, powers and grounds.
Eric Mickelsen That is a very good question!. I wondered why the car would start with the module disconnected, and not with the module connected. Nothing happened to the Can-com lines, so this could not cause the no-start. Than i started taking a look at the white wires. These wires are also communication wires (Lin), but i did not go in to this in the video! Then i realised there was a problem in these lines as you can see in the video! Sharp question!
Brilliant. The key (sorry about the pun) here is that with the module plugged in or not plugged in there was not change in the CAN signal. So not a definite module problem. Dan decided to look elsewhere before condemning the module. Very good call. Like others, I would have ignored the unchanged signal on the CAN lines and changed the module ... and been wrong!
Alex Messina I'm searching high and low on Mitchell for the wiring diagram of the Comfort Access Module showing the inputs from the door antennas. I can't find it. Anyone else?
Comfort access car owner: "Mechanic please I need your help, Im late for a meeting and my car wont start" Mechanic: "Its your door handle, you need to replace it" Comfort access car owner:"I dont think you heard me; I said my car wont start" Mechanic: "Yup, door handle" :-)
So the other guys had the problem to the module but didn't do the extended work you did great great job Dan I learned something from you everyday amigo
