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D4 - Common Faults Quick links to all known common faults and their solutions

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  #21  
Old 25th November 2019, 07:10 AM
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Architex_mA8tey Architex_mA8tey is offline
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I had an issue with a D4 where we though it was the parking brake switch and indeed replaced it, and a couple of months later the same issue occured of the electronic parking brake not releasing. Fortunately I had Vagcom with me and was able to tell the handbrake to release itself!
On further investigation it turned out to be loose wiring / connections where the wiring harness went into the brake module in the LH side behind the boot trim. This was sorted out and all has been fine since - worth a check in case you are getting intermittent connections causing issues
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Last edited by Architex_mA8tey; 26th November 2019 at 06:12 AM.
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  #22  
Old 25th November 2019, 02:30 PM
funkmiester funkmiester is offline
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Many thanks will try both. The BECM is in the post so we will see.
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S8FRD 2002 D2 S8 on LPG 213K just passed MOT, again, no issues. Owned since 2007
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  #23  
Old 28th November 2019, 07:09 PM
funkmiester funkmiester is offline
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Update:

Brand new earth cable with the BECM arrived today and fitted. It was a brand new cable (no kinks) but the female socket for the BECM was smashed off leaving the two pins exposed which is the same as the one I took off. I have a third one on it's way on a slow boat from Lithuania which I ordered first.....
Anyway, no joy, still can't connect to the BECM. Looking at various various diagrams it appears just to be diode?

I tried leaving the handbrake off and the car still cycles itself back on (like the list above just without the Parking brake symbol this time. The P on the gearbox lights and the pump under the bonnet runs- rinse repeat.

I checked the cables that I could find in the boot all seem tight.

Scanned, all codes gone except the BECM no contact.

So Questions:
Does anyone understand the logic of which components can "wake" the car up? At this stage it doesn't appear to be the handbrake.

This is the only code that might meant something from the first scan but it has not re-appeared
02067 - Optical data bus unauthorized awakening request Intermittent
But I can't find anything constructive on the net about it and it's currently not a live code. Car still runs perfectly, just doesn't go to sleep.
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S8FRD 2002 D2 S8 on LPG 213K just passed MOT, again, no issues. Owned since 2007
**60*** Unicorn, 2012 D4 Havana Black, 4.2TDI ~60K miles Cream Leather, 25K of Factory extras including B+O Owned since 04/2018
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