Adblue scam?

[Tubbybear]

Hello, I'm trying make sense of an issue that's suddenly arisen with my Audi A4 2.0D Allroad B9 to do with the Adblue. I got a message saying that it needed some Adblue and so I duly filled it up, but the message didn't go away after driving for a bit, so I've taken it to an Audi garage who offered to do a diagnostic inspection. They came back with a long list of issues and fauls with the car, one of which was 'Particulate trap P2002 fault lagged as static'. It also found the 'Adblue pressure too low, suspect a sensor issue inside the amble tank' There were other faults and recommendations listed but these are two in question for this forum. As my countdown clock on the car was now at 150 miles before it's effectively rendered useless I'm being pressured to get this fixed (I'm not even sure how it's legal to disable my car over a fault like this?) However when I asked to go ahead and fix the sensor, assuming that it would  resolve the problem, they have come back and said I also need to fix the Particulate trap fault or the Adblue issue won't go away. Cost approx £3500! Are these two things linked, is this a common problem and am I just unlucky that both these issues have just happened at the same time. Can anyone help? I'd love an independent mechanic to take a look but not sure how I go about that.

Edited October 13, 2023 by Tubbybear

[coupe4]

hi mark,any main dealer will always give you a list of jobs that need to be done and most can be ignored in my opinion,however id definitely be taking it to a good mechanic for a second opinion before audi do anything to it,greg.

[Goose2017]

Hi Mark, I also have an A4 Allroad 2017 and had pretty much exacty the same problem - car asked for adblue, filled it up and message turned to adblue fault 650 miles no start. It has in the past taken a day or two to go out, but now driven 400 miles and still says 650 no start. Taken to an Audi speacialist (not a dealer as two in London told me to take a hike for a fews weeks and then they could fit me in to do a diagnostic). Faults are Lost communication with reductant control module. and Reductant pressure to low. To fix I need a new Adblue controller £690+VAT and a new pump / tank £941 + VAT total with labour £2,665, so not quite as horrendous, but using a specialist not a main dealer. Having discussed with some Audi mechanics, this seems to be a very common problem which Audi are not being as open about as they might be....

[Hammie1982]

I had a similar issue on my wifes Seat Alhambra.

its a 2015 and after pulling the adblue injector / out of the exhaust end, it was all caked up and crusted up.  We fixed that and a few weeks later it done the same thing.

Being a little bit older and not really "needing adblue" i spoke to a very knowledgeable mechanic or 2 and their advise was "get shot of it, just map it out and the car wont ever look for it again" so thats the option we went with.  the car has been thru the NCT since then and there was absolutely no issue with emmisions tests etc

[Goose2017]

Having ordered new tank and pump from Audi for the Audi specialist to fit, only one component turned up so had to abandon the repair until after holiday and planned to hire a car for the trip. Went to pick the car up and the warning had gone. Garage said they had not reset anything. I am thinking the diagnostics test must have in some way reset the computer but what do I know. Have driven the can with no problems for about 6000 miles. Now asking for Adblue again and have same problem with light not moving from 650 miles no restart. Any ideas?