A8 Parts Forum

A8 Parts Forum (https://forum.a8parts.co.uk/index.php)
-   D4 - Everything Else (https://forum.a8parts.co.uk/forumdisplay.php?f=81)
-   -   D4 gone Haywire-Buckle up its a long one (https://forum.a8parts.co.uk/showthread.php?t=16610)

funkmiester 1st March 2022 10:19 PM

D4 gone Haywire-Buckle up its a long one
 
1 Attachment(s)
I have a 4.2 TDi D4 for about 3.5 years. About 2 years ago pre pandemic it was blighted by a nightmare battery drain, basically the car would not go into sleep mode. It would re-start pumps and lights etc after about 3 minutes and would drain a full battery in a few hours. In the end I took it to a local specialist who spent about 4 weeks with it and Audi UK were stumped. The eventual culprit was a faulty diagnostic unit. 4H0907468. By pulling the fuse from unit the car worked almost perfectly. The only give away was a 0.5 second delay between pressing the button/key and it starting as well a flicker of the needles on the gauge cluster on power up. I drove it around and I bought a second hand module with the supposed correct letter code. It was the one it was supposed to have but it needed a different one. I eventually tracked down a "C" code one but since the car was fine and the pandemic etc it's sat on my desk.
Now to the self inflicted nightmare. With the pandemic it was doing very little mileage and occasionally the battery would completely flatten. It was a Halfords AGM with a 5 year warranty. This was not unexpected the car could sit for 2-3 weeks without moving so was not an abnormal drain. Anyway what you may not know about AGMs is if they are completely drained a few times it ruins them. Like toast. So as I had a 5 year guarantee the battery went back for a new one (on no 3) and occasionally I would charge it properly off the car and back to life.
This is where I screwed up. I was impatient, the car was dead and facing downhill on the drive I decided to jumpstart by connecting to the battery in the boot. I know, I know.
It did eventually fire but was lit up like a christmas tree with all sorts of unusual lights/faults. I have OBDeleven so reset everything but no joy a complete list of all sorts, engine codes, lights, doors everything.
I took it back to the garage and they didn't do much and I suspect the Tech who did the work 2 years ago is long gone as I got a bunch of unconvincing BS from the guy who looked at it. He said it was perfect other than a headlight warning. Actually the Power Steering is non adjustable and super heavy. I drove it home a looked for a fix for the PS.
I went away for the day and the wife took the car and I received a frantic phone call, while driving the car had just started honking and flashing (not the same way as the alarm, just a random flashing/honking). She nursed it home and I talked her through isolating the battery. When I got to it I put the battery back on and it started honking again sounding like a dodgy relay clicking in and out and honking. I disconnected the battery and took it to get a new one as it had stopped holding charge.

Where it is now: I have put the new battery on and ran the engine resetting all the codes multiple times but they just keep coming back.
The main ones are, the horn has stopped but the lights flicker (even when of) and warnings on the dash and stay on even after you lock the car and wait on power off, the rear lights go off but not some or one of the fronts.
The Power Steering is still super heavy.
Every time I do a reset the codes change to another set of codes. I have the manuals and have a decent understanding of the D4.
So I am completely stumped and need help. I've never been so- at a loss with a problem.
I've attached the last code read text file from the OBDEleven reader.
Is there a reliable garage in or around Harrogate/Yorkshire that really knows the D4 and all it's modules, Flexray and canbus circuits.
Does anyone have any suggestions what I might have fried when jumping it from the boot?
The diagnostic unit is still isolated by removing the fuse and I did try putting the fuse back in and doing a reset and it made no difference so I can only assume that's a red herring.
If you have read this far, many thanks for listening.

steamship 2nd March 2022 12:04 PM

Looking through the SSP documents on here, the D4 is a complicated beast.

No experience of them, so this is all based on the log file and the SSPs. Module 09 is missing from your scan, with module 09 being the 'Electrical system control unit J519' found on page 26 of the following PDF:

http://forum.a8parts.co.uk/attachmen...8&d=1434042205

There are several references in the log file of 'lost communication' with a couple of modules, 'Vehicle Electrical System Control Module' and 'Body Control Module'. Maybe if J519 is kaput, it's confusing other modules. See if anyone else comments.

PsYcHe 2nd March 2022 12:04 PM

So usually jumping the battery directly fries the battery control module in D3s, so I'm guessing it's a similar thing in the D4. A lot of those errors will be resulting from the same place and just showing in multiple modules because they all rely on each other.

Not sure if that's the 'Body Control Module' or another module, but I'd look at those places to start with.

tc4332 2nd March 2022 12:14 PM

Touching wood quickly and constantly, I can't comment because to date the only problems I get are low petrol, service due.
But my D3 experiences point to the "missing" module as Steamship says. (thanks Shaun).

steamship 2nd March 2022 12:20 PM

Quote:

Originally Posted by PsYcHe (Post 168949)
Not sure if that's the 'Body Control Module' or another module, but I'd look at those places to start with.

Was wondering if both those I mentioned were names for the same thing, but another scour of the SSPs reveals J393, which from it's description seems to be the 'equivalent' of the Body Control Module. Details on page 10 of the following PDF:

SSP460 - http://forum.a8parts.co.uk/attachmen...9&d=1434042205

Unfortunately that now gives 'funkmiester' at least three possible sources to look at, although my first port of call would be module 09.

funkmiester 2nd March 2022 03:12 PM

Many thanks guys for taking the time to look, also writing it out helps channel the thoughts. I'll start on those modules suggested and see if I can talk to them etc. I'll keep you posted also still looking for recommendations (if you have them) in case I get no-where. This is only a D4, I can't imagine how complex the latest D5 is... Only silver lining my D2 S8 which has been Sorned for 2 years started up first turn of the key and moved down the drive.... Maybe a restoration program is on the cards.

funkmiester 14th March 2022 10:17 PM

Help with part numbers
 
I have been busy for a bit but I'm back now doing some diagnostics and ripping things apart to find part numbers.
Most likely
Electrical system control module J519 Part number 4H0 907 063
And
Convenience control module J393 Part number 4H0907 064 L
I have managed to find a second hand one of these. It is easy to get at in the boot.

The problem I have is the J519 part number 4H0 907 063 isn't readily available second hand. There are many variants with different suffixes (A,AB,B,CD.CB,D,L,CF,BP etc etc) coming from different models including other VW's and other Audis as well a D4 A8 with the right engine and drive side (RHS) but different suffix's on the part number.
I know it is not unusual to change part numbers during a run and as a 2011 mine is a relatively early one.
Is there anywhere to find which would be a suitable replacement for the 4H0 907 063 (without a letter suffix) or find out which suffix would be a suitable replacement? According to a few sites in the states offering new OEM parts, most of the suffix's are compatible. I'm not sure I believe that.
It is also deeply hidden behind the dash above the pedals. I've managed to get clear photos of the parts labels but getting it out looks like a hand shredding experience.
Many thanks as always.

steamship 15th March 2022 03:26 PM

Quote:

Originally Posted by funkmiester (Post 169037)
Is there anywhere to find which would be a suitable replacement for the 4H0 907 063 (without a letter suffix) or find out which suffix would be a suitable replacement?

In terms of a replacement for 4H0907063, it has the following superseded versions, so any of these will suffice. This is from the official parts catalogue:

4H0907063G, 4H0907063BG, 4H0907063BP or 4H0907063CG.

funkmiester 15th March 2022 06:32 PM

Many thanks

funkmiester 24th March 2022 01:54 PM

Progress of sorts
 
5 Attachment(s)
I ordered a J519 and a J393 with as close a match I could the J519 came today part number 4H0 907 063 G as advised.
Absolute nightmare to get to under the dash above the pedals and then getting in to unclip all the connectors was not fun. This is where it got interesting as I finally manoeuvred the old one out it started dripping water out of the casing. Opened it up as you can see and its been sitting in water and gone rusty hence all the random symptoms with the horn and lights, washer etc.
So it seems it was nothing to do with the jump start it was water ingress round the windscreen/sunroof. I sealed the new one with mastic on the upward facing side so if any more water gets in the car it wont get in the module.
After re-fitting the car started, but no dash screen, MMI is very dark, no windscreen washers and the power steering is still heavy.
So I obviously need to code this module does anyone have a list of coding or a link to where I can code the options for my car? Or suggestions of where i can get it done in Harrogate area?


All times are GMT. The time now is 09:37 AM.

Powered by vBulletin® Version 3.8.0
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.