A6 C8 saloon 78k klm Ad blue fault 1000klm

[Coldevolution2]

I had this fault about 6 months ago... but before I had a chance to look into it, the fault cleared itself when parked over night.  Always put in branded Ad Blue (Normally Redex) from a new container to avoid the issue with crystallization of the urea. It has just appeared again and may of course clear itself, but thought I would see if anyone else has had the issue.  And how it ended up.  Been asked to drop car in for software updates... Not sure if this will cure issue from reoccurring.

Thanks in advance for any thoughts..

[Steve Q]

A software update might help. It could be the float in the tank that's got stuck maybe. 

[Magnet]

Hello Ian,

’…always put in branded Ad Blue… normally Redex…’.. Redex is probably the most prolific and one of cheapest available. I’m certainly not saying it’s anything but the best, but it would be good to have hands-on experience from volume users. 
Kind regards,

Gareth. 
p.s. No relation to pal Brendan -? 

[Stevey Y]

11 hours ago, Magnet said:

Hello Ian,

’…always put in branded Ad Blue… normally Redex…’.. Redex is probably the most prolific and one of cheapest available. I’m certainly not saying it’s anything but the best, but it would be good to have hands-on experience from volume users. 
Kind regards,

Gareth. 
p.s. No relation to pal Brendan -? 

Hi Gareth Redex is not cheap or the cheapest, all branded product comes from the same plants just different labelling and if you as I have had to search about for better deals you would soon find out that the average price is over £20 for ten litres, therefore one would conclude there is no such anomaly as cheap adblue, as for the companies proliferating product range, over fifty years of trading and a multitude of products might just indicate they make a decent product otherwise they would have gone bust a long time ago, oldest saying in the world, don't knock it unless you have tried it, I have used both their adblue and a lot more of their in tank DPF cleaner over the years both with good results, after just shy of a million miles I think I should be able to spot the lemon by now.

Steve.

[Coldevolution2]

VCDS cable arrived, did a quick scan.  I note the % urea is 20 and should be closer to 35%.  Also I have nothing coming back from reductive ecu...  Will not clear fault codes as this will disrupt Audi main dealer scan...   Good to know what faults exist before and after main dealer visit.  Voltage on terminals also slightly out of recomended level indicating possible issue with control mod ecu.  Will keep updated in relation to outcome..

Log-182D23756-WAUZZZF23KN036889-78626km-48855mi.txt

[Coldevolution2]

List

Edited November 6, 2022 by Coldevolution2

[Coldevolution2]

Main dealer called to say the car needs a new AdBlue ECU.  Not a big deal easy enough to get, as below on eBay etc..  Not sure how easy to fit, but I did ask what went wrong on such a low millage car. They are looking around 86 gbp on eBay...  Im told approx 2 hours to fit?  Lets see... what happens next.  Recall on A6 C8 version rear suspension anti roll bars, plus 2 software updates.

[Coldevolution2]

Well got a call from main Audi dealer in Limerick.  Said it was the main AdBlue ecu as I suspected from acds scan.  Told me 799.00 euro to replace unit and 180 euro for the acds scan.  Its in their, so as they said this would sort it, I said go ahead...  Was expecting to get a call to pick up the car, but today they called and said its now the adblue quality sensor.... Could of starting replacing parts at my local garage... to solve... they want another 350 euro, and then what ever happens after that...  Very disappointing to be honest, I told them to just give me the car back, no need to replace parts. 

[Coldevolution2]

Checked with Audi Belfast price of parts.  219.60 Adblue ECU  Pressure sensor ( there is no quality sensor? on my car)  130.00 These include VAT. Does anyone have the schematic for the car to see whats involved in replacing parts.  Thanks in advance

 

[Coldevolution2]

I have had a fairly good conversation with main dealer (service manager) where they seem genuinely quite concerned that such a small millage car 2019 model, looking to see if Audi themselves will pick up on the issue. Bottom line the diagnostic scan at 200 euro can tell no more than the scan I did myself.  (i.e Ad blue ecu not responding to scan and Adblue quality below recommended urea quality. posted 6th Nov car was taken to main dealer on 7th)  It looks like when these problems occur Audi has no idea themselves as to the final issues, hence the reason to continue replacing parts until the problem is solved. Of course with this procedure, I can do same in my own garage without the costs of  main dealer ramp.  I guess my main concern now is I no longer have faith in the Ad Blue system, and would no longer feel comfortable taking this car on any form of long journey as this issue may re appear, and the fact I have a countdown until the car will not restart!  This is purely an emissions problem, and does not affect the reliability of what is a fantastic engine. Of course not being able to start this engine or have a current work around is now my issue. My options are now sell the car for a petrol Audi, or carry around spare parts for the Ad Blue with the knowledge of how to replace them.  

[Steve Q]

10 hours ago, Coldevolution2 said:

I have had a fairly good conversation with main dealer (service manager) where they seem genuinely quite concerned that such a small millage car 2019 model, looking to see if Audi themselves will pick up on the issue. Bottom line the diagnostic scan at 200 euro can tell no more than the scan I did myself.  (i.e Ad blue ecu not responding to scan and Adblue quality below recommended urea quality. posted 6th Nov car was taken to main dealer on 7th)  It looks like when these problems occur Audi has no idea themselves as to the final issues, hence the reason to continue replacing parts until the problem is solved. Of course with this procedure, I can do same in my own garage without the costs of  main dealer ramp.  I guess my main concern now is I no longer have faith in the Ad Blue system, and would no longer feel comfortable taking this car on any form of long journey as this issue may re appear, and the fact I have a countdown until the car will not restart!  This is purely an emissions problem, and does not affect the reliability of what is a fantastic engine. Of course not being able to start this engine or have a current work around is now my issue. My options are now sell the car for a petrol Audi, or carry around spare parts for the Ad Blue with the knowledge of how to replace them.  

Definitely worth seeing if Audi will pick up the bill. Hopefully once it's fixed you won't have the issue again. 

[Coldevolution2]

Hi Guys,

Audi themselves will not do anything for me as the car is outside 3 year warranty.  However Audi main dealer have said they will give me goodwill (amazing!)and pay for parts etc, if I cover ramp time.   I had a look for information on C8 model A6 Ad Blue and found a section under SCR = Selective Catalytic Reduction.  I have created a pdf file for information on system Audi work shop manual.  That I can understand whats involved. I have attached.

ADBLUE A6 A7 C8.pdf

[Coldevolution2]

Limerick Audi Dealer true to their word... Car back with new upgraded ad blue tank and ECU, pressure quality sensor also including re-new injector pipes into engine bay,injector working well so only thing not replaced.  All done for around 950 plus VAT... Happy, very happy!  2 years warranty now on system as replaced.  Big thank you to Joe Duffy Audi Limerick, especially Michelle (service manager),  who calmed me down and made everything right with the world...

[Magnet]

Many thanks for sharing your contentment with your main dealer Ian. 
We are so used to hearing tales of (justifiable) discontents, that your post really does make refreshing reading. 
Enjoy the car.

Kind regards,

Gareth. 

[Tomas Donegan]

Hi Guys,

 

Following on from Ian Symington, the same AdBlue Default 1,000 Km has come up on my A4 2016 with 134k on the clock, I've just rang Audi Limerick and it's booked in for Tuesday next week. Will come back and let ye know how I get on. 

[Steve Q]

4 hours ago, Tomas Donegan said:

Hi Guys,

 

Following on from Ian Symington, the same AdBlue Default 1,000 Km has come up on my A4 2016 with 134k on the clock, I've just rang Audi Limerick and it's booked in for Tuesday next week. Will come back and let ye know how I get on. 

Keep us posted on how you get on 

[Coldevolution2]

Just a quick call in to say updated Ad Blue fix, is working well with no issue.  Was worth the visit to Audi Limerick.  Many manufacturers are having issue with Ad-Blue, great to see Audi taking a interest in sorting out customers problems.  2 years in nearly at this point...

[Steve Q]

2 hours ago, Coldevolution2 said:

Just a quick call in to say updated Ad Blue fix, is working well with no issue.  Was worth the visit to Audi Limerick.  Many manufacturers are having issue with Ad-Blue, great to see Audi taking a interest in sorting out customers problems.  2 years in nearly at this point...

Glad you had a positive experience and got sorted 🙂