Page 2 of 2 FirstFirst 12
Results 26 to 44 of 44

Thread: E32 fire warning!

  1. #26
    Join Date
    Jul 2009
    Location
    Richmond, Virginia
    Posts
    1,683
    My Cars
    '88 735i, '06 RSX
    Please sticky this thread so we can avoid any more tragedies. I had no idea about this until after my car was ablaze

  2. #27
    Join Date
    Jul 2015
    Location
    Montreal, QC, Canada
    Posts
    268
    My Cars
    09/87 E32 750iL
    Last weekend I went to a scrapyard and picked up a few diagnostic covers. According to realoem.com all cars from E28 all the way up to E39 use the same part. Unfortunately, that's not true. There is a third version that's being used in cars with ODB II. In our old cars the plug connects the RXD line to +12V and grounds the TXD line. In the ODB II cars, however, both are connected to +12V via a resistor that probably limits the current that can flow.

    Would anyone know what would happen in our cars if we'd pull the TX line up? Would the resistor prevent smoldering wires just as well as a fuse?
    Attached Files Attached Files

  3. #28
    Join Date
    Mar 2016
    Location
    Lincoln, NE
    Posts
    272
    My Cars
    91 735iL
    I want to add something into this...Took my car our for a short drive yesterday. Not even 5 minutes into being on the smoke started to come out from were the fresh air vents/windshield defroster vents on top of the dash. Of course I got freaked out, and pulled over and checked everything. I thought it had something to do with this thread so I removed my diagnostic cap and tried to start the car. My 7 won't even engage the starter without it plugged in. Turn the key and nothing but, put it back on and it'll crank.

    I don't think the smoke is related now (here's to ripping out the dash now) but looks like I'm one of the few that have to have it plugged in. Going to be doing the modification still.

  4. #29
    moroza's Avatar
    moroza is offline MORΩN ΛABIA BMW CCA Member
    Join Date
    Sep 2006
    Location
    BFE
    Posts
    11,090
    My Cars
    E34T
    My E34 544iT (M60 DME, Motronic 3.3 without EWS) had this happen two years ago. I ended up having to take apart the main fusebox and half the interior to repair collateral damage. I disabled and removed the diagnostic cap entirely and noticed nothing changed - no warning lights, everything ran fine. Skimming this thread, it looks like EML is the only system to require the cap in place?

  5. #30
    Join Date
    Jul 2009
    Location
    Richmond, Virginia
    Posts
    1,683
    My Cars
    '88 735i, '06 RSX
    Quote Originally Posted by NE32 View Post
    I want to add something into this...Took my car our for a short drive yesterday. Not even 5 minutes into being on the smoke started to come out from were the fresh air vents/windshield defroster vents on top of the dash. Of course I got freaked out, and pulled over and checked everything. I thought it had something to do with this thread so I removed my diagnostic cap and tried to start the car. My 7 won't even engage the starter without it plugged in. Turn the key and nothing but, put it back on and it'll crank.

    I don't think the smoke is related now (here's to ripping out the dash now) but looks like I'm one of the few that have to have it plugged in. Going to be doing the modification still.
    God that's bringing back flashbacks now. You're gonna have to replace wirining behind the dash now...not a project I envy. Still glad it didn't turn out in total loss. Did the smoke stop? Did you tow your car?

  6. #31
    Join Date
    Mar 2016
    Location
    Lincoln, NE
    Posts
    272
    My Cars
    91 735iL
    Quote Originally Posted by youngbimmer View Post
    God that's bringing back flashbacks now. You're gonna have to replace wirining behind the dash now...not a project I envy. Still glad it didn't turn out in total loss. Did the smoke stop? Did you tow your car?
    I stopped for maybe 45 minutes to try to figure out what happened but couldn't find anything. Was only about a quarter of a mile from my house so I just drove it back and nothing. Last thing I did was replace the cabin filter like a month ago so, I went and checked everything there but still couldn't find anything. Found some confidence and drove for about an hour and still no smoke. Haven't really drove it since but still gonna pull the dash. No clue what it could be..

  7. #32
    Join Date
    Jul 2009
    Location
    Richmond, Virginia
    Posts
    1,683
    My Cars
    '88 735i, '06 RSX
    Quote Originally Posted by NE32 View Post
    I stopped for maybe 45 minutes to try to figure out what happened but couldn't find anything. Was only about a quarter of a mile from my house so I just drove it back and nothing. Last thing I did was replace the cabin filter like a month ago so, I went and checked everything there but still couldn't find anything. Found some confidence and drove for about an hour and still no smoke. Haven't really drove it since but still gonna pull the dash. No clue what it could be..
    That's even more concerning that there is not a specific cause and could be anywhere in the wiring. I hope you get it figured out, please report back what you find

  8. #33
    Join Date
    Mar 2017
    Location
    Israel
    Posts
    3
    My Cars
    E34 525i E30 318i
    Hi,

    Sorry to revive an old thread but it is the best I could find.

    I have been working 2 hours a day, for 10 days on my 1996 E34 525i automatic, weather permitting.
    It's my daily driver for the past 5.5 years.
    The trouble started with a sudden dead battery after parking for the weekend. 0 voltage.
    I brought a replacement battery (under warranty), went ahead to connect it and got a large spark when attaching the second battery terminal. I didn't connect the battery of course.
    There is a short between the positive terminal and the car body. I was surprised the car didn't burn down.

    Ever since I have been trying to locate the short, tearing up my beautiful car in the process..
    Several times I thought I found the culprit, wrongly suspecting old aftermarket alarm systems installed above the pedal area. Took apart the fuse box as well.
    When this didn't help I switched to a more sensitive multimeter.
    Now I have located 2 sources for the short:

    1) When the diagnostic cap is closed, I get a reading of 4KOhms resistance.
    This could be explained by what is described in this thread and can at least be temporarily fixed my removing the cap or isolating pins 14 and 15 on it. I don't really understand why you suggest to fuse it, it could just be disconnected. I have not yet found where the diagnostic cable shorts to the ground but it could be anywhere in the car.

    2) The DME, between terminals 26 and 28 (B+ and ground) gives a resistance of 30KOhms. I don't know if this is normal, as I don't have a replacement DME to compare.

    I am a little afraid to connect everything back together, put the DME in place, leave the diagnostic cap out and connect the battery.

    Does anybody know what the normal resistance of the DME should be?

    I just don't think it is likely I have to 2 problems at the same time, but 30KOhms seems to me too low.

    If I would need a replacement DME, can I just buy one with the same code or will I run into problems with EWS? What do I do then?

    All help will be appreciated.

    Amos,
    Jerusalem, Israel

    original_c5f85da0-99d5-4e93-badc-4397603fd519_PXL_20210126_135415194.jpgPXL_20210121_091321850.jpgPXL_20210126_133125856.jpg

  9. #34
    Join Date
    Jan 2010
    Location
    Brantford ON Canada
    Posts
    1,630
    My Cars
    735iL - 1989
    Quote Originally Posted by amosbmw View Post
    Hi,

    There is a short between the positive terminal and the car body.

    Amos,
    Jerusalem, Israel
    Hi Amos,

    You do not need a sensitive current meter.

    Just connect a small 12V lamp (maybe a 6W dome light) between your + battery post and its cable. The lamp will burn bright until your short is cleared. Then it will go dim or dark. No drama, no sparks, no smoke, just light.

    Now take a look at your "armchair dave" E34 ETM:
    https://shark.armchair.mb.ca/~dave/BMW/e34/e34_88.pdf

    You may say these diagrams are strange, but it's just a new kind of map reading.

    On page 0670.2.00 you can see 4 wires leaving the battery positive post. One of these is shorted to your chassis.

    When you disconnect the correct one, your lamp will go dark.

    To create the sparks you saw, it will probably not be a fuse. It will be one of the thick cables.

    I would disconnect the starter and alternator first.
    Last edited by E32FAN; 01-26-2021 at 08:12 PM.

  10. #35
    Join Date
    Nov 2006
    Location
    USA
    Posts
    1,133
    My Cars
    e34 540ia/e32 740il
    Quote Originally Posted by shogun View Post
    Experiment: Driving with D100 open
    Let's have as many as possible cars drive with their D100 cap removed from the diagnosis port, and collect the field reports from these trials for E32Fan. If a module becomes confused, the car may go to limp mode until re-started with the D100 cap back in place. But this may never happen. This is evidence-based, experience-driven.
    My E32 (US 1994 740iL) is currently off the road as of a couple days ago for more suspension work, but once it's driving again I'll experiment with driving for a couple weeks with the diagnostic cap removed and report back with the findings.

    I have never had an issue with wires on this circuit shorting on my E32s or E34 but it worries me, and I don't want to deal with the aftermath of finding all the burnt areas of wire loom if it happens!
    Last edited by m60power; 01-26-2021 at 08:27 PM.

  11. #36
    Join Date
    Jan 2021
    Location
    Romania
    Posts
    11
    My Cars
    e32 730i
    I found another area that is easly checked and can start a fire or at least a short: the headlight plastic caps:Capac lumini.jpg

  12. #37
    Join Date
    Mar 2017
    Location
    Israel
    Posts
    3
    My Cars
    E34 525i E30 318i
    Thank you E32fan.

    I know the ETM, it's been my reading material for the past week..
    I also started with the starter/alternator on day 1. disconneted all 4 wires coming from the battery and investigated.

    Anyway, yesterday I put the DME back in. Finally I found out, that with the diagnostic cap removed The short is definitely gone.

    I still have to find where the diagnostic cable running between the car modules is damaged.

    I will have to wait for a fair weather day to put the car back together..

    I have to wait for a new gas pedal I ordered as well, because I broke it while working under the dash.

  13. #38
    Join Date
    Jan 2010
    Location
    Brantford ON Canada
    Posts
    1,630
    My Cars
    735iL - 1989
    Quote Originally Posted by amosbmw View Post

    I have not yet found where the diagnostic cable shorts to the ground but it could be anywhere in the car.
    0670.5-04 shows X6002 Pin 15 = RxD (WS/GE)

    0670.2-00 shows X6002 pin 14 = Circuit 30

    Pin 14 is unfused. Our experience is that Pin 15 (RxD, WS/GE) can short to ground in some module.
    In my case it was the A21 Memory Seat controller, X646 pin 5.

    In some cases this melts the WS/GE conductor inside the cable looms.

  14. #39
    Join Date
    Jan 2005
    Location
    Japan
    Posts
    54,654
    My Cars
    11/88 E32 750iL+98 E36M3
    Quote Originally Posted by Calin Ponta View Post
    I found another area that is easily checked and can start a fire or at least a short: the headlight plastic caps:Capac lumini.jpg
    same I found on my 750 years ago, almost bare wires, replaced them with better ones from a parts car , but best is to solder in new wires.
    This, however, was my own fault, because I once tested H1 rally headlight bulbs with 100W instead of standard 55W!
    Last edited by shogun; 02-03-2023 at 10:04 PM.
    Shogun tricks and tips for the E32 series are HERE!

  15. #40
    Join Date
    Jul 2009
    Location
    Richmond, Virginia
    Posts
    1,683
    My Cars
    '88 735i, '06 RSX
    I assume the exposed wire, if touched, can cause a nice short and melt the car down?

  16. #41
    Join Date
    Nov 2006
    Location
    USA
    Posts
    1,133
    My Cars
    e34 540ia/e32 740il
    Quote Originally Posted by youngbimmer View Post
    I assume the exposed wire, if touched, can cause a nice short and melt the car down?
    I think in the case of the headlight or fog light housing wires those circuits are protected by fuse so in theory it should just blow the fuse if those wires short against eachother

  17. #42
    Join Date
    May 2013
    Location
    Canada
    Posts
    1,512
    My Cars
    1990/02 BMW 735iA M30B35
    The headlight or fog light housing wires those circuits are protected by fuse that is far a way till reach the fuse wire will be melted first. It is good to put fuse near head lights somewhere in safe area.

  18. #43
    Join Date
    Jan 2005
    Location
    Japan
    Posts
    54,654
    My Cars
    11/88 E32 750iL+98 E36M3
    All other items are far from the fuse box, no need to put extra fuses. The main function of a fuse is to protect your wiring. NEVER install a larger fuse than given by BMW. Fuses operate because the fuse element is the 'weak link' in the circuit, so that over current will melt it and break the circuit. The time taken for the fuse link to break the circuit (to 'blow') varies depending on the type of fuse and on the characteristic of the device. Where the current carried is very much greater than the rated value (which is usually associated with a fault rather than with an overload) operation is usually very fast. For small overloads, where the current is not much larger than the rated value, operation may take a very long time.
    Fuses are critical in any electrical system and are used to protect a circuit's cabling from excessive current that could lead to damage/electrical fire. Excessive current is most likely to be caused by three things:
    Incorrect wiring - wrong connections as a result of human error
    Damage to the circuit - e.g. a wire working loose or insulation wearing through and causing a +ve wire to short to ground.
    Overloading the circuit - e.g. connecting more pieces of equipment that draw more current than the circuit is designed or, conversely, using cable of insufficient size for the current draw of the intended equipment.
    Shogun tricks and tips for the E32 series are HERE!

  19. #44
    Join Date
    Nov 2006
    Location
    USA
    Posts
    1,133
    My Cars
    e34 540ia/e32 740il
    Yes, like shogun said, no need to put an extra fuse closer to the possible short location for an electrical circuit that is already protected by a fuse. The only case where this would be valuable is if you think that BMW's specified fuse amperage for that particular circuit is too high such that the wiring for the component on that circuit would melt before the 'weak link' of the fuse.

    Regarding the diagnostic cap - I've been driving my E32 for just over 2 years now with the cap removed from the harness plug and haven't noticed any differences from when it was plugged in. One of these days I'll get around to modifying the cap so it is properly fuse protecting the rest of the car's wire harnesses...

Page 2 of 2 FirstFirst 12

Similar Threads

  1. E34 Wanted, E34/E32 Fire extinguisher mounting bracket
    By nitrouso in forum BMW Parts Wanted
    Replies: 0
    Last Post: 11-14-2010, 02:22 AM
  2. V12 Fire Warning.
    By 8Tech in forum 8 Series (E31)
    Replies: 55
    Last Post: 03-21-2009, 09:43 PM
  3. E32: manipulation of the LKM to avoid CC warnings with HID
    By shogun in forum 1988 - 1994 (E32)
    Replies: 0
    Last Post: 12-10-2007, 12:06 PM
  4. firing order e32`
    By danielman in forum 1988 - 1994 (E32)
    Replies: 3
    Last Post: 01-18-2007, 08:58 PM
  5. Fire Warning! Racer Beware!
    By MAkard in forum Track, Auto-X & Drag Racing sponsored by Bimmerparts.com
    Replies: 126
    Last Post: 10-30-2006, 11:59 PM

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •