d4 wiring loom issues
 

just noticed there is nothing whatsoever in the d4 section
for common faults ...


having read a couple of other forums im concerned about the coolant pressurisation problem which now appears to be affecting d4 vehicles

has anyone experienced this as yet ?

no tell more

Not sure if this is relevant but I had a coolant pump of some nature replaced under warranty last summer. My D4 is a 2011 3.0TDI with 60k miles. I wasnt aware of any issues but apparently a fault code flagged it when it was in my local Audi dealer for a software update. From memory it wasnt expensive but I'll have a look for any paperwork that might show a part number if that helps.

Interested in this also...... I have this logged, cleared and comes back

Led me to a few threads like this http://www.audiworld.com/forums/a8-s...rness-2862459/

Due to go in under warranty in a couple of weeks :Confused:

Could have sworn this stuff was in the common faults section like the D2 and D3 sub sections.

Anyway here it is for your reading pleasure

http://forum.a8parts.co.uk/showthread.php?t=8379

V059121012A is the part no. for the coolant pump replaced on my D4.
Google indicates its a small cheap looking plastic pump, no surprise it didnt last long. Not sure it does much anyway as i hadnt noticed any issue prior to replacement or any difference afterwards.
Photo attached from Garage Paperwork. Prices are in € + vat.

http://forum.a8parts.co.uk/attachmen...0&d=1462742458

At that price not the end of the world, so long as it isn't an engine out job to fit it time wise!?

As it was warranty work, I never got to see the Invoice but I would say it was less than 2 hours based on the length of time they had the car.

Would it be cynical to think that in warranty its a "swap the pump and it will be fine" and out of warranty is where the £xxK bills come in!? :rolleyes:

reading the other threads though this is the tip of the iceberg, the liquid is forced down the sleeving of the harness in to modules. then it will start to add up.

from the problems described by other a8 owners
apparently fluid is pushed down the wiring loom into certain connectors
it can actually get that bad it ruins a whole heap of parts

engine wiring loom
ecu
hvac system

im going to get mine checked out shortly to ensure i have not got the start of a very expensive problem to sort

i also think this needs to be taken up with audi u.k and with the dealerships

im going to do my homework on this as it sounds pretty serious
when i do check out my car ill photograph everything so as other owners can get an idea of whats involved

the effected parts appear to be

Transmission Coolant Valve - N488
It looks like the part has already been revised once: 4H0121670A

n509


would be great if someone with elsawin or the likes could put a few pictures up so as we knew what the possible problem could be

if there are any a8 owners up or around south yorkshire and would like there car scanned for this potential problem
please message me im literally 2 minutes from junction 36 of the m1

Keep us posted, it sounds like megabucks to sort if ignored.
It may only be an issue on early D4 models if they have revised the parts already.
When I was looking at used D4's last year, I came across a 2012 one "in preparation" at a main dealer. It had the passenger seat removed, the carpet in the passenger footwell pulled back and lots of trim removed under the glovebox area. The Salesman mentioned it was waiting on some electrical parts as the aircon drains had blocked flooding the footwell ?
I walked away obviously but I wonder now if it was this coolant/wiring issue.

the D4's in the other threads appear to be in the main 2011/12 D4s on fairly low mileage as far as i can see. we are taliking about 3000 to 23000 miles.

one of the guys had a bill for 8K dollars, most of the others were on warranty, so we are looking at multiple modules, and of course putting in a new loom that will probably add a huge amount of hours to the bill.

Found this - suspect it will contain what you are looking for or at least a few pointers?

Good Find. Is there a version available that covers the 3.0TDI engine ?

Sorry I don't have access to a repository, I found it using creative google searches.

I suspect the 3.0 is omitted as the document was dated 2010 the D4 was launched with the 4.2TDi and 4.2FSI engines only?

I've now moved all the D4 information files to Common Faults Sticky HERE now +++
There is a document on there specific to the 3.0 Tdi Engine

going to do the inspection on my vehicle this morning
i will try and get photos of the offending items
so as its easy for other people to identify

right guys
the offending article appears to be accessible by removing your **** guard under the car (be warned it has a lot of screws and fixings )

and carefully removing the plugs to see if they are wet at all

one brown plug and one black one (one of which is difficult to access as its up against the intercooler )

https://www.flickr.com/photos/235252...posted-public/

may just be worth you keeping an eye on your own car

Thanks for posting, I'll add it to my to do list.
Would it be possible to access by removing a wheel arch liner ?

yes for the front plug

however here is one which is sandwiched between the inter-cooler
and the pump itself
this is difficult with the **** guard off
i would say even more so with just the wheel arch removed

hi all

are you all talking about this issue because my a8 is having this error since i bought it

Mine has had a new pump fitted - under warranty so no idea of cost but don't think it was a huge job.

but photos that Nath added, are they regarding my fault with cooling pump ?

i cant find this part as this is the pump is likely to throw fault

according to another thread on different vw/audi forum coolant pump V50 is located in firewall. so basically i need to remove plastic covers next to windscreen and i should see it

ok let me sum up,

my engine is 3.0 tdi. according to audi in my car is only one valve- n509 doesn't exist in 3.0tdi, only n488 and has number 4H0121671D and looks like that:
https://flic.kr/p/HPEtKN

and in my case this valve is located next to gearbox, between gearbox and geabox heat exchanger (small radiator)

also circulation pump v50 has number 059121012A and looks like that https://flic.kr/p/JKX8Va

and it is located in firewall on left side if you look from front of the car
https://flic.kr/p/JKWJdF

https://flic.kr/p/JKWJbr

https://flic.kr/p/Jkam8C

and this error / fault
it is caused by this pump, and needs to be replaced for error to be gone.

thanks

damtom85,

i see it was summer when you changed your pump, don't suppose you noticed if the blowers got warm?

mine are all but stone cold, only just noticed as the weather has turned, and the only error thrown is the same pump error as yours.

makes sence, i think, but don't want to waste £100 on a pump if it's not the fault

cheers

Albert

Hi.

car gets warmer much much quicker than before, I bought used one for £40. audi fits them in A8, A7, A6, A5, A4 so it is easy to find them.

PS. I changed mine 2 weeks ago not in summer. I knew what was the issue but didn't have time to do it. however now weather turned cold I needed to change it. Done it in 20 minutes, difference is huge.

cheers,

peeled the engine bay seal off, tipped the plastics up and mine looks exactly as yours.

ordered one, looks tight to get into, did you remove the wiper arms and take the trim off, or just lift it and squeeze in?

should i replace the solenoid valve too while i'm at it do you think?

Hi.

I removed wipers and lifted trim and squeezed in. there is metal bracket which holds pump with 3 screws and that bracket is bolted with 2 bolts to firewall. pump has 3 pin connector, and you can actually check that pump ( if you buy used one) connecting 12V on outside pins (remember about polarity)

I didn't change valve and I couldn't find any issue with it

I wonder if Audi have improved the part as the early ones definitely seem to be problematic.

revision A, is still the same. I had one from 2012 which was faulty but I bought one from 2010 and it is working. although I spoke with my friend who works for audi and said it is common issue with these pumps not just in A8 but in whole range.

there is revision B but it will not fit A8 as different bracket I believe.