No start because of Doorhandle!

[Music] [Applause] [Music] [Applause] hi guys diagnose down here today we're working on a no-wake BMW 3-series and this car guys has quite a story a couple of months ago no lights would come on on the dash the ignition switch won't work there was a little symbol on the dash and the steering lock the steering lock wouldn't come off the car wouldn't respond on anything so they towed it to a local garage and they changed lots of modules they change the steering column which called the electronic steering lock and it would work because thousands and thousands of euros then it was sent to to a dealership and they actually got it to run and now it's here everything works fine only the Comfort access system doesn't work so they want us to take a look at it so I actually solved the problem today but I want to show you guys step-by-step how I did it so let's go and take a look if your BMW has comfort access you will have these little riches on the handle if it's smooth it doesn't have the system well what the system does is when you have your P in your pocket or in the car vicinity you only have to touch the handle and it will automatically lock or you'll hold the key in your pocket and you will stick your hand through the handle and it will unlock and on this car guys it doesn't work because the key is in the vicinity but it doesn't lock it does on the key itself but it does not on the handle the next thing I did is to check for updates for this car and with this unit you can update all the modules in the car and what it does is compare the software in the modules to the latest software that's available and you can see there are some updates for this car for instance for the telephone you can see this can only be programmed via fiber optic cable we will talk about this later in another episode and what I saw is that the comfort access system is not responding you see it's red and what I noticed is then when you do a quick scan and the module does not respond it does not flag the code so it does not stand out guys so be careful when you do a quick test and the system is not working it won't flag a code so you won't see it so actually when I go back now and I manually select convert access it does not communicate and I miss that guys so what you basically needed to do now is to check for power and grounds and communication so let's see the next thing I did is found out where this conferred access module lives and it actually lives in the trunk and we have to remove a panel in the right side of the trunk and this is where it lives and what I found guys and actually found it like this is the connector was not connected it was not on the module could it be this easy guys well it usually isn't and let's see so with the connector on I wanted to see if I could communicate with the module again so to do that I have to put on the ignition and loop guys absolutely no response as far as not responding any more and look in the dash there's that little symbol that steering lock symbol these symptoms are exactly the same as the customer had months ago this car was never fixed the connector was disconnected and then it started up and they thought let's leave it like this so let's find out we'll take the connector off and see if it will start again so the connector is off again let's see and it starts up again guys so despite the car not responding I still want to see if I can't communicate with the car access model so let's see the comfort axis okay no communication and what I also noticed with the connector connected I could also no longer communicate with for instance Park distance control so with the connector disconnected I can communicate with Park distance control and with the connector connected from the car axis module I cannot anymore so let's pull up a wiring diagram and see what's happening guys so the next thing I did is to check for power and grounds for the comfort axis module and it's all ok so I wanted to see how this thing communicated so I pulled up the wiring diagram and it communicates via these green wire and this orange green wire on this lines over here and actually you see next to it sitting the Park distance control communicating via the same wire guys so when I plug in this module I can no longer communicate with this module and this module so something is happening on this communication lines when I plug in my comfort axis so let's actually find out what's happening on those lines ok guys inside trunk we're right this is the comfort access module you can see I am connected to the green and the orange green wire the connector is disconnected from the module I know you guys are screaming you should have back probe did I know I should only I want to put the connector in and out and it's almost impossible my probes keeps falling out this is inside the car no water here I will fix those wires it will be fine no worries I've got my scope connected my DMT o-scope and this is actually what the communication will look like and [Music] look like it's very healthy guys nothing wrong with it so let's plug in the module and still healthy communication guys so uh nothing wrong with the communication so is this it guys is the module busted we've got good power and grounds I checked that we've got healthy communication it's still going and I actually put in some known goods with this scope with one click of a button you can put the known goods in and out so it looks exactly the same so that's all good but it's a bit of a mystery guys if I could could powering grounds and I've got good communication why can I not communicate with it so would call it a broken module but before I do that I want to check some things because these modules aren't cheap so let's check a little bit more ok guys pulled up another wiring diagram for this Comfort access system looking for the inputs of the system it actually has four antennas for recognizing the key if it is in the vicinity of the car for the inside and the outside of the car there's one two three four antennas and then over here we've got our our door handles let me see this is the passenger's side and this is the driver's side I want to check the driver side first you see it got its own ground it got his own feed coming from a fuse so there's a signal wire going to the Comfort access module it is a white wire it's located on in one so let's see what we've got i unscrewed the module only two plastic nuts holding it down for easier access disconnect the connector just cover there's a little clip over here get it out of the way it slides right up and then we want to check the signal wire on pin number one it was a white wire and here it is and what I want to do is get it out of there so uh there's a little clip here holding it down push on it you should be able just slide it out let me see a little bit a hard time there it is okay what I want to do just get it out of the way and connect the module again watch it without the cover you can actually do it both ways now so the power on this side is wire I checked it before so those like this so let's check if we can communicate okay the white signal wire of the left handle is out of the connector and guys still no response still cannot communicate so no chains so let's go to the next okay guys this was a signal wire for the for the driver door handle the white wire check that one disconnected it made no chains so let's move on to the next one it's also a white wire is the signal wire for the passenger side handle and it's on pin number four so let's disconnect that one and see if we got any change guys so let's get pin number one back in again and it locks right in and you got a white wire on pin number four so one two three four white pin or white wire I mean get that out push in the clip comes right out put it back in the module see if there's any change so white wire signal wire from the passenger door handle taken out of the connector so let's see what we'll do and the car starts right up guys let's see [Music] is actually our comfort access module and we can communicate guys no fault codes so that's great okay guys passenger side door handle let's got its own feed over here going to a fuse and it's got its ground over here and I'm pin number one on the door handle is our white wire going to pin number four on the comfort access module and with this pin out of the connector we can communicate with our module again so something wrong over here so we got to find out what it is we would expect the C voltage passing through this wire over here all the way to our module and when we put our hand on the handle we change the field strength over here and it's transistor over here will very rapidly short or pull down to ground this voltage over here creating a signal so let's see what it does our signal wire from a passenger side door handle expect to see your voltage over here no voltage maybe even a ground can't be sure with an LED gotta use a bulb style test light connected to battery positive if that is if this is ground the bulb should light as you can see guys it actually does this wire is fully grounded and it shouldn't be so let's compare it to the other side driver-side are known good pin number one also white wire and what have you got we've got a voltage so definitely something wrong with this wire over here so let's trace the problem down so uh the wire from the door handle is going all the way through the car ending in the door and lawyer so behind this rubber there's a little hex bolt holding it down you can slide it out this cover and actually if you move it forward you can easily slide the whole handle out well at the end of the handle here's our white wire going to the handle so let's disconnect it and look if I wire is still shorted so I've got the door handle off now on the passenger side the connector on the door handle disconnected so I want to see if this wire is still shorted out because it could be shorted inside the door handle or it could be shorted on the body of the car somewhere [Music] so let's find out my test light connected to battery positive let's check if the test light works it lights so nothing guys so nothing wrong with this wire our problem was in our door handle okay our passenger side door handle our problem must be in this handle somewhere so let's take a closer look and this is our connector and this is our problem guys some serious heat damage over here so diagnose confirmed guys this handle shorted internally I want to show you guys real quick with our short to ground out of the way so our door handle off the key is actually on the roof of the car and let's touch the handle great guys that's a fix okay guys not a quick thing I want to show you that even though this handle is not connected that connector is not going anywhere so no voltage going to the control module and we have communication now we can see it's not operated and put your home on the handle and it actually is operated right now so it is functional but even though the handle on the right side is not connected it does not set a fault code guys so very hard to diagnose this it does not set fault codes on these handles tomorrow I will put a new door handle on this car and it will be fixed and really fixed this time and when you think about it how cool was this one guys we actually had an O start because of the door handle only on my channel guys so I made of scene easy on video actually a lot of work went into this car we had no communication everything looked fine when we had communication we had no fault codes so I'm never easy guys but that's why they brought the car over here and eventually we found the problem so I hope you enjoyed my videos if you did please subscribe to my channel give me a like and if you comment below this video I will try to respond okay so diagnose then see you next time guys [Music] you

Channel: DiagnoseDan

Views: 213,824

Rating: 4.9710522 out of 5

Keywords: Bmw, car diagnose, bus communication, doorhandle, gmto, Diagnosedan, fix, diy, 3 series, scope, comfort access, no start, Premiere_Elements_15, waveform, gmto scope

Id: B7gggowzPSE

Length: 21min 17sec (1277 seconds)

Published: Fri Jul 28 2017