Intermittent electronics error fault, when cold. Engine runs fine.

[lello7]

A mystery is baffeling me. I always not deadlock the doors with the key fob. (press it twice). Started doing that since i once had a problem with the central locking not working, and thus no other doors than the drivers door would open (with key). This has worked for over a year. New year, new problems..

 

Whenever the weather is could (i live in sweden, imagine), the electronics of the car shut off. 

 

When that happens, the doors wont open by remote, the boot wont open, the AC wont work, nor the climate (compeletly off). The wipers will not work, the indicators will not work, the park aid will not work, the radio will not work, you name it will not work. The tail light will blink, and the numberplate light will blink.

But the engine starts without any problems. I First suspected the battery, so i put it on constant charge, (charged to 14 volt)..but still when the car gets cold, the problem is there. 

 

When trying a SCAN in that state, the only Modul recognized is the ECM, with the following codes.

18043 and 18045.

 

Now this can be "fixed" the only thing i need to do is to put a HEATer under the drivers footwell (left hand driven car), and let it stay on for aprox 5 minutes. Then a put the key in to the ignition, and voila, all is sorted, and i hear relays or something making noice. Works every time.

 

Codes reset before car gets cold, and malfunctions, and heat treated, A new scan is here:

(all new codes directly after heat and functionen car) 00457, 01299, 01317, (01274), U000200, U1111000, 00849, 01317, 00625.

 

"01274 Air Flow Flap Positioning Motor - FAULT" is an old code, the flap for the climate motor is not working.

 

Sorry for my english.

 

 

HELP, i dont have electricity everywhere i park, thats is why this solution is not permanent...my heater is electrically driven 😛

 

PS, i have TPMS light, ESP and ABS light on in dashboard when i start the car in this faulty condition (i dont have TPMS in my car). But when heat is on, then all ligth go away after restart the car.

Edited 28 December, 2022 by lello7

[UrbanPanzer]

First check would be the battery terminals are clean and tight.

 

Second would be worth a quick continuity check of the main fuse links connected on top of the battery

 

If both of those are good........ then it sounds like possible water ingress to the BCM under the dash................thats what controls pretty much everything and for you to loose all those electrical items,

it must be related, it's located up behind the interior fusebox on the drivers side by your knees, hence putting a heater there fixes it.

 

 

[lello7]

Thank you for your advice. I also suspected a loose connection to the BCM. I started with the easy part, removed the earth terminal from the car, and then removed the BCM, by releasing two connectors, and after released the BCM, and it slided down. 

It looks really really clean, and no surprises there, since it's never parked outside in rain. 

At home I park it in a garage with ambient temperatur (now days its sub freezing, water would be ice. Hence heating as I do should result in melting of ice, and thus more water.... 

And at work I park in garage with 20C degrees, 68Fahrenheit.

Never seen a dropp of water under my feet. 

 

Can add some information. This have been ongoing since September, every day its is cold outside. So I did not use the car for over 2 months. 

The car was parked and not touched for more than to months in heated garage, October, November, and I got it again mid of December. The car did behave as normal,(opened with remote, I was surprised since I thaugt the battery would be dead after 2 months) the car started easy, and no faults. 

I parked in garage at home, ambient temperatur, next day it would not open with remote (as september) , and all errors back. And every time I leave it for more than an hour or so, in cold weather, the problem is there. 

 

Next to test is to see if the plus battery terminal is clean as per your suggestion, and also measure continuity of the (big) fuses on the battery. The 5amp fuse looked fine, tested previously. 

 

More ideas would be nice, like mounting a diesel heater in the car compartment haha... 

 

Edit: mounted back everything this morning, and now after 2 hours, the problem is back ( I was hoping that removing and reconnect would mayby solve something :-() 

Heated for 3 minutes, locally under bay, and voila.. Damn it. 

 

Edited 29 December, 2022 by lello7
Added info with Edit note.

[lello7]

I have now measured Continuity, at all 6 Fuses, (one did not have a cable), all showd 0.1 (measurement error from my multimeter, it never show zero).

I opened the door (remote)....(no heat) and after few seconds, disco light, the light in the roof started to blink (NO key in ignition), and i could hear som relay clicking. Tested to touch every relay i could see, but none felt "clickin". I also laid my hand on the BCM, and no klicking there that could be felt. 

 

I could hear the ????? fuel pump???, prime, in the same frequency as ONE off the clicking noice...ended upp disconecting the EARTH lead on the battery, and left the car,

 

What is next :=(

[Breezy_Pete]

Are there some standard blade fuses near those strip fuses?

[lello7]

Hi and tanks for joining in:-) 

 

Yes, there are 3 standard fuses. All three are good, specially the 5 amp one, since I tested it with 4 amp load and it was all good 🙂

[lello7]

Car locked. 

[UrbanPanzer]

Ok, so next port of call for me is to check the door loom between the drivers door and the A pillar has no broken wires ( in the rubber bellows)

 

This a common break point on the Fabia 2 and although you have what I would call "excess" symptoms, they are all related to potentially when the car is "woke up" which is when the BCM "should" get both a remote unlock and "wake up "signal, it's "possible" that one or more broken wires is causing spurious messages / short to grounds or both, who knows how that BCM is wired on the inside, the clicking relay and flashing light points to something either failing in the BCM OR it's getting mixed messages..............overall DEF worth a look at the door loom in my opinion, if not to just rule it out.

Edited 29 December, 2022 by UrbanPanzer

[lello7]

 😞, good idea, I will try checking it next month, although I purchased the car 2020-Januari, from a private person (only owner). 

On the way home I noticed that no WINDOWS could be opened, the side mirrors could not be adjusted, no heated mirrors, I called him and he probably lied and said he had not noticed. Saw at least one complete broken cable, and several on their way. 

 

I bought a completely new lhd door loom and fitted it in Feb 2020. Everything startted to work after that.

 

More ideas please:-) 

 

Sidenote:

I now accedently destroyed my Radio (all three fuses checked, one in radio and two under steering wheel) it's completely dead, but I can communicate with it thru "Obd" reader. I will just buy a new one of the car ever get sported. 

[lello7]

The wires in the loom look OK, and as you can see i have fitted a custom made loom, since the old design was bad:-(

 

Today, I turned the heat on, and after 30 minutes went to the car, tested remote, and it worked 😞

 

What is causing this 😞

[UrbanPanzer]

So, with this "heat" making it work,

 

is it possible there is a dry / cracked joint in the BCM and the heat expands it and makes the connection.............hence everything works ?

 

You are possibly at the point now in my opinion when you have to "try" another BCM, either new or good used, NOTE you would have to "copy" the settings of the old BCM to the new one, to do this you need VCDS or similar...............however "if" you can get a BCM from a car of the same spec and age, it would potentially be a straight swap to atleast see "if" thats the issue

[lello7]

This is the best idea yet in my opinion, a crack will most likely behave like this. Trying a new bcm is buying a new one unfortunately, I don't know anybody in uppsala with a skoda fabia. I will start looking at scrapyards, they will take approx 250£ without shipping. Can it also be a fuse or a relay under the drivers area that is semi broken och have a cold joint, if so, I will start next year and going through the electrical diagrams. (over 1500 pages, but will narrow down to J519 related pages.) 

 

I am now not at home, and have left the car Outside, the temperatur is below freezing, - 5 Celsius... I have no electricity near by, so have for the first time left the car Unlocked (in order to be able to open all doors (rear child locked). I will update what happens tomorrow 🙂

[lello7]

Today I wanted to access the boot... I have no release lever next to the drivers side, only remote, or electric rear button on the boot. As we all know, it needs electricity/signal to release.. Controlled by BCM or other modul...

No heat accec. 

 

I opened front door, (manually, it was not locked), opened the engine bay, disconnected the battery... And reconnected (with a spark) and instantly pressed boot release on remote, boot opened, and the car went back to "dead state" at least I could open the boot this way. 🙂

[Breezy_Pete]

In your photo of the BCM on Thursday morning,  the connector pins don't appear to be very clean. I expect it is just the light/contrast/reflection of the picture, as you say in words that 'it looks really really clean'.

Do have any other photos that maybe show connector pins more closely?

[lello7]

Stay tuned, I will take new pictures when I release the BCM again. But not until next year, since I am not at home currently 🙂

That photo was taken in a semidark garage and fast:-). 

Mayby I should use electronic cleaner before I mount it again 🙂

 

Visually it looked clean, no corrosion nor grease on the contacts 🙂

 

I am VERY comfortable when it comes to electronics... 

 

When I park the car next year (tomorrow) it won't be using it for a while.. So I am going to disconnect the battery and remove the BCM again (and the radio since I might have broken the front PCB yesterday...) 

While BCM is of the car, I will clean it, and disassemble it (have to drill in the plastic housing on some points I guess??) saw no screws, and something else than the side clips is holding it together. 

I will use a microscope to check all suspected points.. Any advice before I proceed? 🙂

[UrbanPanzer]

A used one in the UK is not that bad, like below..........def cheaper than 250 Euro even with shipping out to you.

 

https://www.ebay.co.uk/itm/274856141347

 

 

Edited 31 December, 2022 by UrbanPanzer

[lello7]

Thanks for the link, I tryed to buy it (maybe to late to make decision before new years) but it will not ship to Sweden, mayby I will contact the seller and see if an exemption can be made. I will however still need an vcds or similar, and I don't know anyone with such device. Maybe a link to the cheepest thing would be nice?

I guess I will connect it to the Obd socket, pick the BCM(ce) modul and read/save the configuration? 

And after plug in the new one in the car and Write the config? 

Can I have a newer BCM, I guess not? 

[UrbanPanzer]

yes you need VCDS to configure properly.

 

Yes you can probably only buy a later "new" version, probably ends with "R" instead of "H"

Edited 31 December, 2022 by UrbanPanzer

[lello7]

Happy new year 🙂

 

Pictures, not the best, noticed my camera was not clean.. 

Was only able to add one.. 

 

[lello7]

I have today cleaned every single pin in the BCM, with a small cloth and 99.8%Iso propanol. (they seemed sturdy, and not wiggly).

It's now in a "oven" at 37 degrees Celsius, so it will dry completely. 

May a relay do this behaviour? 

[lello7]

I have now fixed my Radio. 

So, when temp is "room" temperature or above, the car behaves perfectly. And no sign of any codes (but the AC flap code). 

 

The weekend is coming, and I will then remove the BCM and start drilling in it. 

 

"Testing" a new BCM is buying a new one, and then the coding.. Expensive test :-).

 

[varooom]

https://laga.se/bil/oem/6R7937087R

Not sure if that is any good for you price wise, but that should work with your car.

 

Any of these should work

6R7 937 087 H  Z00

6R7 937 087 K  Z00

6R7 937 087 M  Z00

6R7 937 087 P  Z00

6R7 937 087 R  Z00

6R7 937 087 R  Z0J

[lello7]

Wow, what a great site 🙂 I have now bought one, waiting for it to arrive.

And I also need to find someone that can Code it/copy my old. 

 

I can add that it's Not a fuse or relay issue for sure. 

My generator is also good, sits around 14.4 volt when driving... 

 

It 99% the BCM. 

 

For the first time since a bought the car, new codes have appeared regarding tvs diodes, 03301,03302,03303 and 03304.

I know this will be sorted when a new revision is installed of the BCM (h version before week 2011 45)

[Breezy_Pete]

I hope you will still do a post mortem on your old BCM ?

[lello7]

What are you interested in seeing Breezy_Pete? I can not attach any more pictures in this therad 😞

Can I pm you pictures? I only Saw a clean pcb with clean pins:-(