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Thread: ME7.2 broken pins repair

  1. #1
    Join Date
    Jan 2020
    Location
    UK
    Posts
    2
    My Cars
    E34 525i,E38 740i,E53

    ME7.2 broken pins repair

    Hi all,

    I love my 2000 E38 740i sport, and having saved it from the scrapyard by doing the TCG myself a couple of years ago I felt like I can do anything now to keep it alive. Well, transmission rebuild excluding. But yet again I had quite a roller coaster in the last days with what I thought will be a 2-3 hour fix. It’s a bit longish so just bear with. It was mostly forum posts and write ups that helped me to do the TCG job at the time so I’m just hoping it might help some other poor soul in the future. Here goes:


    For some time I was struggling with intermittent engine failsafe, gearbox failsafe, complete non start errors and some time ago I diagnosed the not uncommon pin corrosion case made much much worse by fire extinguisher powder and liquid ( 2 different extinguishers) after a big scare but small and very short (15-25 sec) fire caused by leaking injector seal after TCG job. I rushed it was my fault. Lesson to others, never leave the ECU box uncoverd, for one thing if it rains it goes straight in and also in case of fire. Back to the DME topic, I suffered for many months with problems and major unreliability of the car which was mostly scary as my wife used the car quite often to commute and she would not have been able to jiggle the harness or disconnect reconnect the ECU’s to get going again. Sorry I digress.


    After some digging around I figured that instead of learning everything about coding ECU’s the easiest repair in my case will be soldering a whole new connector after seeing a YT video I ordered the part and got to soldering. Unfortunately instead of taking it seriously I jumped in with crappy 15 bucks worth of soldering iron and the cheapest suction piston. Baaad bad bad idea, after a de-soldering test run on a cheap spare transmission control module I realized that mechanically chopping the connector off and then unsoldering the individual pins one by one is the way for me. It kinda worked but the cheap tools still made a bit of a mess around the pin holes but nothing major. Main problems came when I re-soldered the brand new shiny connector and used ample amounts of solder without thinking where does it all go. Yep you guessed right, what a muppet, I ended up with unknown amount of unknown sized blobs between the plastic backplate of the connector and the PCB. To my surprise though the car fired right up and ran for 15-20 minutes beatifully that night, I was over the moon. Next morning however was back to earth real quick, the car started only just and ran very lumpy, engine failsafe, transmission failsafe quickly followed. And then came the burning electronic component smell from the dme. Postmortem found at least one ignition mosfet fried (easy fix) but mostly the shorts from the bad soldering became blaringly obvious. TOD recorded.



    Plan B, secondhand ecu from ebay I had knocking around for a couple of years, how am I going to get this to work. Days and days of reading followed. Eventually got to the stage, where I could flash updates via WinKfp and realized, it will not be enough to solve the EWS error codes. New discovery, virgin DME can be paired with existing ews, keyring and keys. Found zarboz’ and geargrinder’ and many others posts and contacted dudmd also to pay for the solution. Unfortunately at this time in life I couldn’t afford his quality service and being across the pond also posed a possible time delay endangering my work (to get there requires me to drive 1000+ miles through europe).


    So after getting some help from the aforementioned 2 esteemed members and following their procedures on virginizing a second hand unit I gave it a shot. Had a lot of difficulties along the way mostly with not having a powerful charger to stabilize voltage (ended up using 3 smaller ones) and also a bad connection between the round pin adapter and K can usb cable). For the future I would like to do it “on the bench” so to speak, just wasn’t equipped with a good variable power source and also wasn’t sure whether to use the K cable or if I need a BDM interface, so if anyone could send me pic of their setup, that would be great. Anyhow as with ME7.2 the necessary partial reading writing can be done on the car ( after soldering a wire to the correct pin on the pcb itself for entering boot mode and also removing all sources of disruption like a BT obd2 interface in your obd port or IR mouse controller in the usb port) that’s what I went for. Eventually I read, patched, wrote to the flash rom following instructions but in my case I had no luck settling the replacement dme with my ews rolling codes (crank but no start). The clusters ( 6 bytes ?) on the 3 addresses known to be cleared in the virgin dme remained clear ( not sure what those numbers are ? ISN perhaps) and I could not get inpa to reset nor realign ews with dme. After I weighed up all the possibilities to troubleshoot I realized that there is way too many variables like my connection issues , my laptop the second hand dme itself the software used, the way the software was used, DIS or VM not wanting to communicate with the car ... you get the idea.


    Running out of time I decided for one last shot before begging to borrow a car from family or friends for a month or two until saving up for a ews deleted DME from the pros. There isn’t much point for a tune in my case as I’m running on LPG anyway ( less than half the price of petrol across Europe) and a generic tune would probably just throw check engine lights all the time , also after doing the guides, chain and the vanos seals I am very happy with the output from the 4.4 lump. So I took to a sledgehammer kind of approach. Got myself quickly a cheap but miles better soldering station with heat gun and digital temp. settings and de-soldered the eprom chip from my original unit and soldered onto the replacement one holding my breath along the job whether I won’t fry the chip. Happy to report I got either lucky or the time spent learning has paid off as the second attempt (had some cold joints the first time around) resulted in a working dme. Little tinkering in inpa realigning ews and deleting a zillion error codes and onto the glorious moment when you hear that first sputter just before the engine fires up. Almost makes it all worthwhile.

    In retrospect, having invested in a decent soldering equipment before tackling 200 something soldering joints twice over would have been a more sensible approach. Also saving up first and buying an EWS deleted DME or cloning the original would have saved me some time. On the other hand I love learning new stuff, and I did learn a lot about how our cars operate electronics wise.


    For the time being the car runs, although it is still riddled with error codes and amber lights relating to dsc. For instance the steering angle sensor has me puzzled, the control module itself has no errors and appears to be reading both brushes and everything, but dsc module has steering sensor error and middle dash amber light coming with it. I will try to swap it (have a recycled one off the bay) but I suspect it won’t solve a thing. Oh and the dsc module has had its trifecta lights disease repaired few years back with a lifetime guarantee by bba reman here in UK so I’m assuming this module itself is fine. Also had a surprise when the alarm went off about 10 hrs. after a short drive around town and I realized the battery was completely drained, so something major is staying awake (navi disconnected), because that is just way too much for a usual current leak ( 3 months old 110AH battery) in such short time.


    Also one thing I’m not sure of is if by transferring the AM29F0400BB chip, did I move the program including the original maps or are those things stored in a different chip. Just wondering if the dme is not suffering from some kind of mismatch as it had an update flashed through winkfp but then the original eprom came on later and it doesn’t know anything about that?
    Last edited by rocky340; 01-19-2020 at 10:16 AM.

  2. #2
    Join Date
    Jan 2020
    Location
    Toronto
    Posts
    3
    My Cars
    2000;X5 4.4, 1999 328is
    Quote Originally Posted by rocky340 View Post
    Hi all,

    I love my 2000 E38 740i sport, and having saved it from the scrapyard by doing the TCG myself a couple of years ago I felt like I can do anything now to keep it alive. Well, transmission rebuild excluding. But yet again I had quite a roller coaster in the last days with what I thought will be a 2-3 hour fix. It’s a bit longish so just bear with. It was mostly forum posts and write ups that helped me to do the TCG job at the time so I’m just hoping it might help some other poor soul in the future. Here goes:


    For some time I was struggling with intermittent engine failsafe, gearbox failsafe, complete non start errors and some time ago I diagnosed the not uncommon pin corrosion case made much much worse by fire extinguisher powder and liquid ( 2 different extinguishers) after a big scare but small and very short (15-25 sec) fire caused by leaking injector seal after TCG job. I rushed it was my fault. Lesson to others, never leave the ECU box uncoverd, for one thing if it rains it goes straight in and also in case of fire. Back to the DME topic, I suffered for many months with problems and major unreliability of the car which was mostly scary as my wife used the car quite often to commute and she would not have been able to jiggle the harness or disconnect reconnect the ECU’s to get going again. Sorry I digress.


    After some digging around I figured that instead of learning everything about coding ECU’s the easiest repair in my case will be soldering a whole new connector after seeing a YT video I ordered the part and got to soldering. Unfortunately instead of taking it seriously I jumped in with crappy 15 bucks worth of soldering iron and the cheapest suction piston. Baaad bad bad idea, after a de-soldering test run on a cheap spare transmission control module I realized that mechanically chopping the connector off and then unsoldering the individual pins one by one is the way for me. It kinda worked but the cheap tools still made a bit of a mess around the pin holes but nothing major. Main problems came when I re-soldered the brand new shiny connector and used ample amounts of solder without thinking where does it all go. Yep you guessed right, what a muppet, I ended up with unknown amount of unknown sized blobs between the plastic backplate of the connector and the PCB. To my surprise though the car fired right up and ran for 15-20 minutes beatifully that night, I was over the moon. Next morning however was back to earth real quick, the car started only just and ran very lumpy, engine failsafe, transmission failsafe quickly followed. And then came the burning electronic component smell from the dme. Postmortem found at least one ignition mosfet fried (easy fix) but mostly the shorts from the bad soldering became blaringly obvious. TOD recorded.



    Plan B, secondhand ecu from ebay I had knocking around for a couple of years, how am I going to get this to work. Days and days of reading followed. Eventually got to the stage, where I could flash updates via WinKfp and realized, it will not be enough to solve the EWS error codes. New discovery, virgin DME can be paired with existing ews, keyring and keys. Found zarboz’ and geargrinder’ and many others posts and contacted dudmd also to pay for the solution. Unfortunately at this time in life I couldn’t afford his quality service and being across the pond also posed a possible time delay endangering my work (to get there requires me to drive 1000+ miles through europe).


    So after getting some help from the aforementioned 2 esteemed members and following their procedures on virginizing a second hand unit I gave it a shot. Had a lot of difficulties along the way mostly with not having a powerful charger to stabilize voltage (ended up using 3 smaller ones) and also a bad connection between the round pin adapter and K can usb cable). For the future I would like to do it “on the bench” so to speak, just wasn’t equipped with a good variable power source and also wasn’t sure whether to use the K cable or if I need a BDM interface, so if anyone could send me pic of their setup, that would be great. Anyhow as with ME7.2 the necessary partial reading writing can be done on the car ( after soldering a wire to the correct pin on the pcb itself for entering boot mode and also removing all sources of disruption like a BT obd2 interface in your obd port or IR mouse controller in the usb port) that’s what I went for. Eventually I read, patched, wrote to the flash rom following instructions but in my case I had no luck settling the replacement dme with my ews rolling codes (crank but no start). The clusters ( 6 bytes ?) on the 3 addresses known to be cleared in the virgin dme remained clear ( not sure what those numbers are ? ISN perhaps) and I could not get inpa to reset nor realign ews with dme. After I weighed up all the possibilities to troubleshoot I realized that there is way too many variables like my connection issues , my laptop the second hand dme itself the software used, the way the software was used, DIS or VM not wanting to communicate with the car ... you get the idea.


    Running out of time I decided for one last shot before begging to borrow a car from family or friends for a month or two until saving up for a ews deleted DME from the pros. There isn’t much point for a tune in my case as I’m running on LPG anyway ( less than half the price of petrol across Europe) and a generic tune would probably just throw check engine lights all the time , also after doing the guides, chain and the vanos seals I am very happy with the output from the 4.4 lump. So I took to a sledgehammer kind of approach. Got myself quickly a cheap but miles better soldering station with heat gun and digital temp. settings and de-soldered the eprom chip from my original unit and soldered onto the replacement one holding my breath along the job whether I won’t fry the chip. Happy to report I got either lucky or the time spent learning has paid off as the second attempt (had some cold joints the first time around) resulted in a working dme. Little tinkering in inpa realigning ews and deleting a zillion error codes and onto the glorious moment when you hear that first sputter just before the engine fires up. Almost makes it all worthwhile.

    In retrospect, having invested in a decent soldering equipment before tackling 200 something soldering joints twice over would have been a more sensible approach. Also saving up first and buying an EWS deleted DME or cloning the original would have saved me some time. On the other hand I love learning new stuff, and I did learn a lot about how our cars operate electronics wise.


    For the time being the car runs, although it is still riddled with error codes and amber lights relating to dsc. For instance the steering angle sensor has me puzzled, the control module itself has no errors and appears to be reading both brushes and everything, but dsc module has steering sensor error and middle dash amber light coming with it. I will try to swap it (have a recycled one off the bay) but I suspect it won’t solve a thing. Oh and the dsc module has had its trifecta lights disease repaired few years back with a lifetime guarantee by bba reman here in UK so I’m assuming this module itself is fine. Also had a surprise when the alarm went off about 10 hrs. after a short drive around town and I realized the battery was completely drained, so something major is staying awake (navi disconnected), because that is just way too much for a usual current leak ( 3 months old 110AH battery) in such short time.


    Also one thing I’m not sure of is if by transferring the AM29F0400BB chip, did I move the program including the original maps or are those things stored in a different chip. Just wondering if the dme is not suffering from some kind of mismatch as it had an update flashed through winkfp but then the original eprom came on later and it doesn’t know anything about that?
    I have been going through exactly the same procedure. I managed to solder the new connector nicely to my original dme but for the life of me I cannot get the dme and ews to synchronize. I keep on running into issues and I don't know if it's my Galleto tool or my installation, or the software I'm using. When the alignment went out on yours what tools did you use to re sync them?

  3. #3
    Join Date
    Jan 2020
    Location
    UK
    Posts
    2
    My Cars
    E34 525i,E38 740i,E53
    Quote Originally Posted by Lucasffer View Post
    I have been going through exactly the same procedure. I managed to solder the new connector nicely to my original dme but for the life of me I cannot get the dme and ews to synchronize. I keep on running into issues and I don't know if it's my Galleto tool or my installation, or the software I'm using. When the alignment went out on yours what tools did you use to re sync them?
    If you have the original board undamaged, it should resync easilly, I used Inpa on mine, however for good measure i cleared the error codes first from ews, dme and the other important modules as well like dsc, transmission.. In inpa there are two commands under the engine management menu ( shift+F6) , I cant remember which worked but I got a positive message when it worked, something along the lines that a start is enabled ( not exact phrase it was in german). Sorry I'm not familiar with Galleto.

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