K-BUS Problem - struggling to diagnose.

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ph1l1p

Member
 Chichester, West Sussex
Hi everyone

i’m having an issue with the K-BUS in my e85. I have attached an image of the codes i have scanned from the KOMBI.
135, 32, 198.

So far i have tried:
Battery charger
Disconnecting each module 1-by-1 from the kbus, as per the bmwgm5 guide.
Checking all fuses

But nothing has made any difference so far.

Does anyone have any ideas as to what else i could try? I suppose i could try disconnecting every module from the kbus and connecting one at a time. If that doesn’t work, what else could cause this?

It is also worth noting that on occasion, all systems will come back to life for a few seconds before cutting out again. This is the part that seems most bizarre. Could there be some sort of relay or ground that is causing this issue to be someone intermittent? If so, where are they? I haven’t been able to find info on where the grounds are on this car, so i haven’t been able to check them but would like to be able to eliminate that possibility.

Thanks in advanceIMG_1772.jpeg
 
I’ve got a guide- will send

The other thing I’d look at is the kbus comb- on a pre facelift that’s behind the fuse panel. The alternative on a facelift is a bunch of wires that terminate in a similar area
 
bigwinn said:
I’ve got a guide- will send

The other thing I’d look at is the kbus comb- on a pre facelift that’s behind the fuse panel. The alternative on a facelift is a bunch of wires that terminate in a similar area
Click to expand...
Ah brilliant, thanks.
I had a go at the KBus comb. There is a guide on bmwgm5.com which i tried where you disconnect one at a time, but it didn’t help. something else i want to try is disconnecting all at once and connect one at a time incase multiple modules have failed.
 
I will find the guide later

From memory there are 7

One either side of the boot behind the carpet
One near the fuse panel, two on the opposite side drivers footwell
Two in the engine bay either side of the bay near the suspension towers
 
bigwinn said:
I will find the guide later

From memory there are 7

One either side of the boot behind the carpet
One near the fuse panel, two on the opposite side drivers footwell
Two in the engine bay either side of the bay near the suspension towers
Click to expand...
no worries. i’ll take note of these, but there’s no need to rush to find the guide tonight; i probably won’t even start looking until tomorrow afternoon.
 
bigwinn said:
Good luck bud!!
Click to expand...
Good afternoon,
I have an update. I checked all of the ground points (that i could find - not all of the ones in the guide were in my car, specifically the ones in the dash and kick panels. I suspect they are different on RHD.) and they all appeared to be secure and in good condition.

I then went on to do another test i have been meaning to do for a couple of days - remove every connector from the K-BUS comb at once to see if it's a multiple-module issue. However, even with every connector removed from the comb, nothing came back online. This leads me to believe that it isn't one (or many) modules in particular, but rather some kind of external factor causing the issues.

So, now my question is: what things could be causing this? I checked and my battery runs at a good voltage, all fuses are okay, and now i know the grounds are okay. What else?
 
Is the kbus circuit damaged anywhere?

It’s a difficult one to trace… I’m doing it myself at the momentIMG_8731.jpeg
 
bigwinn said:
Is the kbus circuit damaged anywhere?

It’s a difficult one to trace… I’m doing it myself at the momentView attachment 283688
Click to expand...
That could be it - one of the codes i'm getting is a short to ground, which would make sense if the cables are damaged. How should i look for this? Are there some specific locations that the cable is visible from other than where it connects to the comb?

Also, wouldn't my previous test rule out issues with wiring being that none of them were connected to the comb and the issues were all still present?
 
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Chris @Street has a much more logical mind than mine when looking at kbus issues

As far as I recall the kbus wire is the same colour around the car so you can spot it quickly and test via probing

Mine is going to be an easier task in one way- this loom is past saving so needs full replacement
 
bigwinn said:
Chris @Street has a much more logical mind than mine when looking at kbus issues

As far as I recall the kbus wire is the same colour around the car so you can spot it quickly and test via probing

Mine is going to be an easier task in one way- this loom is past saving so needs full replacement
Click to expand...
Okay. I'll drop him a message. Thanks.
 
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