Problems with the starter, the electrics and the general module in an e34 from 4/1995

[German518iowner]

Hello there,

Thank you for accepting me into this forum. First I'd like to apologize for the rather lengthy post and for possible mistakes in my language.
I'm from Germany and I own an E34 518i sedan from 4/1995 that I indeed love very much. But recently the car has been troubling me. I'm having serious electric failures.

The problems are as following: No crank when turning the key, no power windows, no sunroof, no central locking, no radio, no interior lights, no wipers at all (not even the highest setting).
The car starts when you push it downhill and when you bypass the starter in the big wiring loom right below the windshield.

I did a lot of research on the internet, including this forum in particular and found some threads that described the same problems.
This is the link to the thread that appeared to be most promising: (http://www.bimmernut.com/forum/archive/index.php/t-44670.html).

However, none of the solutions that were offered in this thread (and all others on the internet) have worked for me. I'll now give a short recap of what I found and what I tried:

All fuses in the engine bay are ok. The fusible link next to the battery in the engine bay appears to have no hairline cracks. I found that my carpet on the left hand side of the car was very, very wet. Water was also beneath the left rear seat where the rear-power-distribution-box sits. This must be somehow related to my problems.
I checked all fuses at this location and they are also ok.
I removed the seats and the carpet to dry them. I then followed the instructions from the thread that I found on this forum and opened the wiring loom that sits beneath the rear carpet on the left side close to the rear seat. There were many corroded connections which I soldered back together. This brought the interior lights and the radio back to life. All other systems stayed dead. I removed the relay-module and the general-module and the three relays from the rear-power-distribution-box and dried them over night with dry beads. No effect.
I then concluded that my failures must stem from a broken general module. I bought a used GM and a used RM from ebay with the correct part numbers. (GM = 61358368571 / RM = 31351379741).
Today I tried to install them which brought no change at all.
I then removed the GM out of curiousity and suddenly the engine fired right up when turning the key. Naturally, all other systems didn't work.

I feel like I'm in a dead end now. Why does the engine suddenly start properly without the GM? Is it possible that the GM interferes with my anti-theft-module? (I should have the EWS II). I tried finding the EWSII but had no success. Is there maybe a way to bypass it? (Not trying to steal a car or do anything illegal).
Does anyone have an idea which other wires I should check?

A bing thank you in advance to everyone who has an Idea how to help me.

Regards from Germany!

[shogun]

As you are from Germany, here is the detailed German language training hand book ZKE = GM/RM central chassis electronics with wiring diagram.
I had a look thru all the functions like wiper, doorlock heating, interior light, wiper pressure, washwater etc, the only thing I can imagine which stops the engine to start is the crash sensor http://www.e32-schrauber.de/bmw/s-zke.htm
On E32 the crash sensor is hidden under the seat frame of the rear seats, shown here http://bmwe32.masscom.net/johan/electronics/rearseat.html
my
Then on my E32 there is a hidden fuse here for DWA http://www.bimmerboard.com/forums/posts/236235/ not sure if that is same on E34, maybe someone can comment

[German518iowner]

Hi Shogun,

thanks for your reply. I honestly don't know if my car even has a DWA since it has a very basic extra equipment (Executive Ausstattung). I did, however, find the little blue crash sensor (German = Stoßschalter) which was hidden quite well under the left rear seat. Is there any way to check if that crash sensor is still working properly? It rattles when you shake it - but I guess that's how it is supposed to be.

A few days ago I found the leak where the water was getting inside the war. There were two quite large rustholes (both ca. 5 cm2 in size) in the drivers footwell, right beneath the location where the loudspeaker is mounted. Thanks to my dad's remarkable welding-skills, these holes were fixed quickly.
After I sealed the welding properly, I'll finally be able to assemble most of the interior back together so that I can drive the car again.

I was also thinking about the wiring loom that leats to the trunk hatch. I read that these wires break quite frequently and since I've had problems with the central locking at the trunk-lock for ages, maybe that's the culprit.
Maybe the GM somehow notices that there's a short in the trunk-wiring-loom and registers this as a possible break-in-attempt, so it sends this information to the EWS which blocks the starter? That's why the car starts fine without the GM...?

I'll report back on monday.
Until then best regards from Germany.

[shogun]

As far as I know the Stossschalter rattles a bit, that is normal. I have a spare one, that also rattles
There must be a reason that there are rust holes. Do you have a sunroof? If so, thru both A-pillars go the water drain hoses and end under the door, you can even pull it out behind the speakers in footwell. In case the drains are clogged, water rises there and rust starts , see here pictures https://forum.e34.de/thread.php?threadid=169578&hilight=Ablauf+schiebedach
how to make new drain holes https://forum.e34.de/thread.php?threadid=182478&hilight=schiebedachablauf
Under the doors all the wires go from rear to front/front to rear.
Trunk hatch wire loom in most cases breaks on the Touring, but also on sedans, you can also check that , some threads with faults caused by this
https://forum.e34.de/thread.php?threadid=279192&hilight=heckklappenkabelbaum
https://forum.e34.de/thread.php?threadid=279010&hilight=heckklappenkabelbaum
I would suggest you register on the German E34 forum and post there in which part of Germany you live and if there is someone near by with a diagnostic software which can diagnoze you car and then you know what is wrong and can repair based on that info.
For example in case you live in Memmingen oder München, contact Markus525itouring

[632 Regal]

Trunk loom wiring failures are quite common. I had quite a few with shredded insulation causing odd problems that you wouldn't think possible. Definitely worth a check. Hopefully all your issues will go away.

[German518iowner]

Hey guys,

thank you for your replies which I appreciate very much.
Yesterday I checked my trunk-wiring-loom. Though there were some cables with a broken insulation, the wires themselves were intact on all cables. The cracks in the insulation are so tiny that I don't believe that a short would be possible. I'll still insulate all of them properly, though.
For now I have reassembled my car's interior and kept the GM uninstalled. This way I can drive the car, though very limited.
Honestly, I could live without the power windows and the central locking. The thing that gives me headaches is the windshield wipers. There's no way to use the car without them since Germany is a very rainy country.

My dad proposed that we bypass the motor of the wipers and install a switch on the inside of the car. Does anyone have experiences with laying cables from the engine bay to the interior?

My next guess would be the doors. Maybe there's a short in one of the door-wiring-looms.

I also bought a used crash sensor (Stoßschalter) and will replace it as soona s it has arrived.

Until then, best wishes.

[shogun]

Often the wire loom from A-pillar to door breaks And usually the driver's door. That causes a lot of problems, as these are connected with the GM.
Here is the eba for electric windows, there you can see how to unlock the plug between door and A-pillar https://bmweba.com/eba-01-29-9-786-757/amp/

Reparatur meiner Türkabelbäume http://www.7-forum.com/forum/showthread.html?t=118598&page= this is a pdf, you might need to register there first to open the file
http://www.7-forum.com/forum/showthread.html?t=28333&page=#post1211542

[German518iowner]

Hi Shogun,

thank you for these detailed information.
In order to test if the door-wiring-looms are causing the problems, I thought the following: I will disconnect the wiring looms to the drivers door, reinstall my GM and test out the functions.
This way the (maybe) broken wiring loom would be out of order and no longer be able to cause problems, right?
Or am I imagining that the things are too easy?
Otherwise I'd surely have to remove some of the interior again to access the wiring loom inside the A-pillar, which would be a shame, since I just reassembled everything a few days ago.

Regards from Germany.

[shogun]

Maybe that will not work (not sure) as the GM is always checking and wants feedback from microswitches etc.
The problem of broken wires can be between A-pillar and door, but also inside the door, example here , click on the pics Kabelbruch Tuer http://bmwe32.pagaduan.org/
The easiest and fastest would be if you find someone with a diagnosis software for these old models. On the German forums for E34 they usually recommend to buy the diagnosis tool from https://doitauto.de/
They also have a FAQ and forum, maybe you ask there what you need https://forum.doitauto.de/

Or find someone near your home with such a software, as I recommended before.

[German518iowner]

Hi guys,

My dad and me bypassed the wipers today - they're now powered over the cigarette-lighter. Kinda feels like a Frankenstein-BMW rotfl
Tomorrow I will get my car diagnosed with a (hopefully) proper software-tool. I'll also replace the crash-sensor.
BTW, today I also replaced the 80a fusible link in the engine bay just to be 100% sure. Unfortunately, it had no effect.

Regards from Germany.

[German518iowner]

Hi guys,

after my buddy used the diagnosis-tool, these are the error codes we found:

Fehlercode: 255
Fehlercode
- Fehlercode nicht definiert.

Fehlercode: 17
Schlüssel 2
- Schlüsselcode unbekannt/nicht gespeichert.

Fehlercode: 65535
Schlüssel 1
- Schlüsselcode unbekannt/nicht gespeichert.

A rough translation into english:

Errorcode: 255
Errorcode
- Errorcode not defined.

Errorcode: 17
Key 1
- Keycode unknown/not saved

Errorcode 65535
Key 2
- Keycode unknown/not saved

I think it's like I guessed: Some short or broken wire is registered by the GM and sent to the EWS, which interpretes it as a break-in attempt and accordingly shuts everything down.

I have another question: If the EWS is engaged, does it also block the use of the power windows and the sunroof?
I could imagine that it just shuts down the entire GM.

Best regards from Germany!

[shogun]

All info lead to EWS.
Windows and sunroof: never heard that the EWS blocks these, EWS is a drive away protection.

[German518iowner]

Hi,

if the EWS is not blocking the windows or sunroof, the error must not be in the EWS alone. My guess is a short in one of the door wiring looms.
I'll check these next week. Thank you very much for all the help and ideas you already provided.

Until next time

Regards from Germany.

[genphreak]

I don't think those error codes are much to worry about, except the first 255 error- that may, or may not, represent something very strange: Mostly likely an 'undefined or unexpected' problem, as you may well know. If it has EWS- so uses a transponder key/RF ring around the ignition barrel, the last two errors may be saying the car does not recognise the code. Have you tried programming the key to one of the 10 key memories? In DIS, you can see each one used, was your key shown in the list of keys trusted by the EWS/ECU? I suspect your root cause is actually preventing power to the second module/antitheft box under the rear seat, amongst other things around the GM. But the antitheft module was an optional feature, so yours may not have it. Either way, power from the rear distribution unit/GM/antitheft probably goes to the OBC and EWS module with the blue connector beside the steering column, beside the knee bolster. This disables the starter motor and the ECM from running fuel and spark, IIRC. But not windows etc.

When was yours built? IIRC, EWS II is 6/95 (depends on production/market). Are you sure yours has EWS? Is it EWS I or EWS II? If so there is a module under the dash. Supplying power to one of its pins allows the engine to start.

What diagnosis tool did you use? BMW EasyDIS is very good for e34 via the ADS interface.

Have you verified the body electronics (50A) in line fuse is not hairline cracked/rusted/blown? This is not by the battery, it's under the rear footwell carpet, drivers side on a LHD V8.

One solution is to strip the seats and carpet out get a new body wiring harness from a good e34 (same build/same options) and fit that, or at least to replace the left side and everything around the rear power distribution box. Repairing the cracked/oxidised wires is fraught with pain- there are so many small connections. How is the state of the power distribution connectors, especially the GM ones, under it? If oxidised around the pins, resistance can build up down the wire (water can seep down each wire around the copper strands a long way, causing oxidisation and resistance which may be a root cause for a failing GM or DWA, let alone the connectors rusting). If you have EWS II should be another module sandwiched in between the seat support and the rear power distribution box, you can only see it when you unbolt the plastic 10mm nuts holding the distribution box and pull it back out a little to find see where the antitheft/alarm module is hiding. It is not mentioned in the official EWS technical info like this http://www.unofficialbmw.com/images/BMW_EWS.pdf

I had a later 1995 520i here for a while, it had locking and starting problems too> The wipers, radio and windows, may have worked or not (I can't remember) but to make it lock and drive I disconnected the antitheft module. I never tried removing the GM.

PS. Without your supplementary wiring, do your wipers work on full speed? I have a euro 1995 540i (7/95) here with the same problems you describe, except its wipers work fine on full speed setting. I haven't tried to run it without the GM, yet. To make it run pull one of the pins high on the EWS unit (it may have been pin #8 in the blue connector, I can't remember for sure), this enables the engine to start and run. No windows, no locks, no slow or intermittent wipers. Right now, I have the interior out, and am replacing the body loom. It is taking far too long though, as I'm building a house, and that takes priority!

[shogun]

According to info from German forum: Alle E34 ab 1/95 haben EWSII = all E34 from 1/95 have EWS II. Es besteht aus der Ringantenne am Zündschloß, dem EWS-Steuergerät in der Lenksäulenverkleidung und dem progammierten Steuergerät DME für den Motor.
Before only the simple EWS I

[genphreak]

According to info from German forum: Alle E34 ab 1/95 haben EWSII = all E34 from 1/95 have EWS II. Es besteht aus der Ringantenne am Zündschloß, dem EWS-Steuergerät in der Lenksäulenverkleidung und dem progammierten Steuergerät DME für den Motor.
Before only the simple EWS I

Thanks for correcting me Shogun. One thing very important to be clear about, apart from the crash relay and the 'submersible' 50A in line fuse in the rear footwell, is that E34 has its EWS control module by the column, beside the drivers' knee but that this relies on numerous inputs, as you can see in the EWS technical info. However many E32/E34 also have an antitheft box (as Shogun mentioned earlier to check its fuse). It is hidden by the GM power distribution box, under the rear seat and is critical to engine start. BMW troubleshooting info focused EWS generally across all chassis seems to omit this unit's input to the immobilisation system. However it provides one of the inputs that EWS module needs to allow start. I suspect that when the loom is oxidised, that and many other GM connections fail and cause these kind of massive faults.

One tip: don't go looking for an immobilisation relay, these only exist in EWS I cars. EWS II incorporated this as a smaller, more reliable relay, hidden inside the EWS module, as well as improved logic and starter motor lockout (when engine turning).

With mine, the 'protection relay' under the rear seat (rear distribution box) is activated/pulled high. I remember seeing on the schematic that this many of the the major body circuits to turn off together (wipers/windows/roof/radio, etc) . Yours is probably the same- if so, it will get warm after a while wit just the battery connected and no key inserted. So you can check it by waiting 30mins or so and simply placing your finger on top. Also the battery will run down quicker, due to parasitic drain, of course. I disconnect mine to stop that happening. What causes the protection relay to trigger is the cause of our problems; likely GM or loom-related. So my money is on the rusty wiring and connections under the rear carpet and power distribution box given that both our cars got 'very wet feet'

[German518iowner]

Hi guys,

Thank you so much for all your input. Since you asked a lot of question, I'm gonna answer them one by one:

>Have you tried programming the key to one of the 10 key memories?
No, I've never tried this. I know there is a tutorial for this in my "very good" repair-manual. I'll give it a try.

>When was yours built?
According to my VIN, my baby was built in 4/1995

>What diagnosis tool did you use?
I honestly have no idea. It wasn't mine, it belongs to a friend of mine. I'll ask him what the software was.

>Have you verified the body electronics (50A) in line fuse is not hairline cracked/rusted/blown? This is not by the battery, it's under the rear footwell carpet, drivers side on a LHD V8.
I found a 50a line fuse in the big wiring loom right under the windshield in the engine bay which was perfect. But I assume that it wasn't the right one. I inspected the wiring loom around the Power-Distribution-Box very thoroughly and I'm sure there was no 50a line fuse. Since they're not too small, I should've noticed it. I will give this another try, though.
I assume LHD V8 means Left hand drive with a V8 engine, right?

>One solution is to strip the seats and carpet out get a new body wiring harness from a good e34 (same build/same options) and fit that, or at least to replace the left side and everything around the rear power distribution box. Repairing the cracked/oxidised wires is fraught with pain- there are so many small connections.
My dad and me did exactly this. We inspected every connection in that loom that we found. Many were corroded and we soldered them back together. This, however, had no effect. The connections were all beneath the Rear-power-distribution box and right next to the left rear seat. Are there more connections, closer to the front perhaps?

>How is the state of the power distribution connectors, especially the GM ones, under it?
They all look perfect. Not a single bit of rust at the GM or RM or their connectors. We also opened both modules and they looked perfectly clean on the inside.

> If you have EWS II should be another module sandwiched in between the seat support and the rear power distribution box, you can only see it when you unbolt the plastic 10mm nuts holding the distribution box and pull it back out a little to find see where the antitheft/alarm module is hiding.
This confuses me. I'm 100% sure that there are only two black boxes in the Power-box: The GM and the RM. There are also a few fuses (not many) and three relays. I'm 100% sure there is no other black box in or around there. The only other thing is the tiny blue crash sensor. We pulled the power-box out very far, btw.

>I had a later 1995 520i here for a while, it had locking and starting problems too> The wipers, radio and windows, may have worked or not (I can't remember) but to make it lock and drive I disconnected the antitheft module.
Are you talking about the module under the rear seat or about the one in the steering-column?

>Without your supplementary wiring, do your wipers work on full speed?
Nope, they don't work at all. Which is strange since I read in many threads that they should work on the highest setting.

Also something strange happened: I tried returning my new GM to the seller. (Of couse I said it's broken, don't blame me, I need that 40 Merkel-Dollars back). He accepted and paid me back my money. But the he did NOT want the GM back?! I suspect he might have know that it's busted, sold it anyway and now that I wanted to return it he does not bother to get it back. I think I'll try buying another one.

Today I noticed that I still have some water leaking in. The body-sealant wasn't dried properly and the water found it's way inside since it's raining 5 days a week in Germany. Thank god it's just very little. It's all so tiresome, boys...

Until then, best regards to everyone. And thank you again for all your help!

[shogun]

The fusible link(s) are always close to the battery. So if the battery is under the rear seat, one wire with a fusible link goes from battery under rear seat to the B+ pole and from there to the e-box. The fusible link is close to the battery under rear seat.
The other one goes from the battery to the driver side fuse/relay box under rear seat to power that.
In case the battery is in engine bay, see here http://www.bmwe34.net/E34main/Maintenance/Electrical/Fusible_link.htm
All E32 have 2 fusible links, in case of E34 it depends on the built year, and most probably engine type (I have no details on this) read this thread https://www.bimmerforums.com/forum/showthread.php?1531141-Fusible-Links&highlight=fusible+link
The 1995 US spec ETM unfortunately does not show the 518i, starts with 525 http://shark.armchair.mb.ca/~dave/BMW/e34/e34_95.pdf
that shows on page 0670.2-01 2 fusible links, F97 goes to B+ junction box in engine bay and from there to the front power distribution box.
and fuse F0 is 80A and goes to 0670.2-07 page , rear power distribution box. In this case the battery is probably under rear seat passenger side.

also on this German E34 DIY it is not clearly mentioned which model has the battery in engine bay and which under rear seat http://www.ah525i24ve34.at/HTML_ah525i24ve34/HTML_PROD/E34_TECHNIK/E34_technik_elektrik_batterie.html

[632 Regal]

I found this little tidbit:


Drive Away Protection System (EWS)Model: EWS I/EWS II/EWS III/EWS III DE31/E34/E36/E38/E39/E46/E52/E53Production Date: All since 1/94

http://www.unofficialbmw.com/images/BMW_EWS.pdf

[German518iowner]

Hi guys,

i really tried my best to find that 50a fusible link. Though I did find one, I'm quite certain that it's not the correct one. I uploaded some pictures to imgur to show you what I found.
Please report to me if the link isn't working or if the pictures got deleted (no idea how long they stay up on imgur). Anyway here's the link to the pictures: https://imgur.com/a/W9CkCA9

I the first picture you can see the location of the fusible link that I found in the engine bay. I cut open the heatshrink and checked the link: It's perfectly ok, no cracks or anything, which you can see on the 2nd and 3rd picture.
But I'm very unsure that this even is the fusible link that you've told me about. On all the pictures I saw in that one thread that shogun sent me, the 50a fusible links were always close to the battery, and they were in the wires that came directly from the battery. This one is not. Also it was in a green cable and not the typical red cables on all the pictures. Could it be that this is just the wrong fusible link?

Genphreak, you said this: "Have you verified the body electronics (50A) in line fuse is not hairline cracked/rusted/blown? This is not by the battery, it's under the rear footwell carpet, drivers side on a LHD V8."
Are you talking about the wiring loom that goes from the a pillar, drivery side to the rear-power-distribution box?
This would make sense, since that wiring loom got very wet which could have damaged the fusible link. Unfortunately I'd have to strip the interior again to check that which I can't do right now since it's cold as **** and raining all day long.

In the 4th picture you can see my power distribution box witht he approx. location of the tiny blue crash sensor. In this picture, the GM is removed. The RM is still installed. I checked thoroughly - there is no other module/ black box around there. And yes, I did thake the yellowish carpet out.

Thanks for your help guys and have a nice weekend.

Best Regards from Germany.

[shogun]

The pictures work. First time that I see a fusible link in that location in the engine bay. But the colour the green wire is strange, normally a fusible link wire is red colour. Also the blue thick wire there seems to be not original (?). Maybe it was installed later not by BMW. Try to find out where they go from ....to
Is the battery located under rear seat passenger side or in engine bay? Both was possible on E34.

[German518iowner]

Hi Shogun,

My battery is in the engine bay. I also tried looking for the fusible link under the rear seat where the battery would be located but could not find anything.
You are correct, the blue wire was installed by my dad and me. It connects two wires that were used by the workshop where the car was (without success) being diagnosed after getting towed from my house be the ADAC (German Drivers Club).
The mechanics at the workshop used the wires to bypass the starter in order to test if it was still working.
My dad and me connected these two wires and installed a button switch which could be used to bypass the starter on demand.
Why did we committ such a weird act of Frankenstein-experiments, you may wonder. Well, the answer is simple: Before we found out that the car starts fine after pulling the GM, we were looking for an improvised way to get it running. And a switch is much nicer than bypassing the two wires with an additional wire. I'm 100% sure that this little "feature" is not messing with the car. All problems were there before and nothing changed after we did install the switch.

Anyway, my hope is on the two new GMs that I ordered from ebay. I also thought about replacing the K15 relay which controlls the power given to the GM and RM. I read this on this website: http://www.ah525i24ve34.at/HTML_ah525i24ve34/HTML_PROD/E34_TECHNIK/E34_technik_elektrik_zke.html

Thank you and have a nice sunday.

As usual, best regarsd from Germany.

[shogun]

o.k., battery in engine bay, that is important for us. As a general rule we can say the fusible link is always close to the battery. Looks like it is a 50A fusible link.
Here - that is again a US 525 - they show that that fusible link is 80A http://www.bmwe34.net/E34main/Maintenance/Electrical/Fusible_link.htm
the failure syndromes they mention there = Failure syndromes: Intermittent simultaneous failure of wipers, sunroof, windows, central locking, radio, No power, like if the battery was dead = that is mainlyl GM related = Zentrale Karrosserie Elektronik.
It may be that your 518 has only one fusible link.

still searching in the net for a matching Stromlaufplan / wiring diagram, the German E34 forum has these https://www.e34.de/tips_tricks/schaltplaene/schaltplaene.htm

here we come closer, 1994 518i is listed there, wayback machine helps https://web.archive.org/web/20070416030057/http://www.carsoft.ru/avtorepair/bmw_e34/E34.html
check it, not all pages work there.
German language Werkstandhandbuch Schaltplaene E34, also includes 518 https://www.ebay.at/sch/sis.html?_itemId=350987861496&_nkw=BMW+E34+Baureihe+5+E32+Baureihe+7+Bj+1988+Wer kstatthandbuch+Elektrik+Elektronik&_mPrRngCbx=1
maybe the cheap CD will do instead of the books. Or here in Augsburg per book 50 EUR https://www.ebay-kleinanzeigen.de/s-anzeige/schaltplaene-bmw-e34/995737140-241-7525
Original BMW Ordner
Modelljahr 1988 525i,530i,535i, 1988 520i,524td, 1989 525i,530i,535i,M5, 1989 518,520i,524td, 1991 518,520i,524td, 1991 525i,535i,M5 2 Ordner, 1992 518i,520i,525tds 2 Ordner, 1992 525i,535i,M5 2 Ordner, 1993 518i,520i,525tds 2 Ordner, 1993 525i,M5 2 Ordner, 1994 518i,520i,525td/tds 2 Ordner, 1994 525i,M5 2 Ordner, 1995 518i,520i,525td/tds 2 Ordner, 1995 525i,M5 2 Ordner, 1996 525i,M5 2 Ordner, Preis pro Ordner, Versand gegen Portogebühr

[German518iowner]

Hi guys,

my car broke down on my way to work tonight. Here's what happened. I was driving around 50km/h when I noticed that my gas pedal was very sluggish (Schwergängig, not sure of correct translation).
So I pressed it down with a bit more force. It suddenly gave in and my engine fired up to 6000rpm even when I let my foot of the pedal.
Panic-stricken I came to a halt and turned off the engine.
I then removed the cover of the bowden-cable over the intake and tried to examine it.The bowden cable was very loose and flaccid. Since the cable is held in place inside some kind of plastic-screw, I tried screwing it back in a little, so it would be tightened again.
I started the engine again but it immediatly fired up to max rpm again, so I quickly turned it off. The cable is NOT broken, however. I can press down the pedal and the throttle valve moves.
I then called the Auto-Club and got the car towed to the a workshop nearby.
I read a bit on the internet and learned that this could be caused by a broken or dirty throttle valve. I'll go to the workshop tomorrow morning, right after completing my nightshift at work. Does anyone have an idea what might have caused this?
Hell, this was scary, especially since the engine was completely cold. I hope that the 5 seconds of max rpm didn't damage anything.

As usual: Best regards from Germany.

[shogun]

I assume nothing happened to the engine, there is a RPM limiter as a safety, cuts off the fuel.
Looks like your bowden cable is stuck. Here is the part number, recheck the p/n with your VIN http://de.bmwfans.info/parts-catalog/E34-Sedan/Europe/518i-M43/L-M/mar1994/browse/pedals/accelerator_pedal_bowden_cable/
Gaskabelzug 35411162171 abt. 15 EURO.
There are BMW Throttle safety clips, scroll down here http://www.nmia.com/~dgnrg/for_sale.htm p/n 35401165393 Prevents throttle cables from detaching, which can cause dangerous unintended acceleration
make one DIY http://i106.photobucket.com/albums/m249/GimmieSumMo72/740iL/DSC00075.jpg

The plastic screw is basically the problem, here a cheap fix , Throttle Bushing repair for $1.72 https://www.bimmerforums.com/forum/showthread.php?2287424-Throttle-Bushing-repair-for-1-72

[German518iowner]

Hi guys,

the high-rev-issue was fixed easily. It was just a dirty throttle valve that got stuck. After spraying it with brake cleaner, everything is now fine again.
Today I installed two more GMs. Unfortunately it brought no change at all.
I'm gonna focus now on finding that damned 50a fusible link.
I will also revisit the wiring loom under that carpet on the left side of the car. I'm sure the culprit must sit there.
I'll keep you updated about any results.

As usual, best regards from Germany!

[632 Regal]

the high-rev-issue was fixed easily. It was just a dirty throttle valve that got stuck. After spraying it with brake cleaner, everything is now fine again.


The throttle body could be worn causing the issue as well. Definitely do a good inspection on it!

[German518iowner]

Hi guys,

I did it! The BMW is running great again!
The culprit was a 50a fusible link under the rear seat in a small black box. It appears as I have one rare BMW that has two black boxes for the fusible links and no fuses under heatshrink.

Thank you to everyon who helped me.

Until then,

Best regards from Germany!

[genphreak]

Hi guys,

I did it! The BMW is running great again!
The culprit was a 50a fusible link under the rear seat in a small black box. It appears as I have one rare BMW that has two black boxes for the fusible links and no fuses under heatshrink.

Thank you to everyone who helped me.

Until then,

Best regards from Germany!

That's really great news. Well done for sticking in there FTW! These problems can be so frustrating, but now you can enjoy your new life with the old-school e34

So 518i has its body electronics 50A link under the rear seat, before it feeds the main body distribution box back there? Interesting, but in a black box you say? Or is it a cover that opens to allow you to change the fuse? Where? Near the power distribution box LHS, or the open area where the battery normally is on 6 and 8 cylinder models?

The 80A one under your windshield had us wondering, it looked factory to me and for a car with the battery under the hood, that'd have been good enough for the 'loom' wizards in the 90s. These days the looms are all made by robot, not hand-bound with PVC and fabric tape like BMW had been doing since WWII until it introduced the e39 which was designed with Computer Area Networking (CAN).

Again, great work, and thanks for keeping us up to date on your troubles!