Audi A6 C7 CNHA P204F AdBlue problem

[Inmedi]

Hello Everyone,

I have a problem with Audi A6 C7 2.0 TDI CNHA 2014.

Information popped up that in 1000 km I will not start the car (that's true - it won't start, just read the errors to add 50 km range).
I read the error codes and got:
28653 - Reductant System Performance Bank 1
P204F 00 [039] - Malfunction
Not Confirmed - Tested Since Memory Clear
Freeze Frame:
Error status: 00000001
Error priority: 2
Error rate: 1
Mileage: 261,712 km
I have never been any similar error like e.g. Nox sensor error. Only this P204F.
Clean error codes doesn't reset the counter on dashboard.

I have done:
- checked reductant injector, quantity test - I got 25ml. Long term adaptation is 1.00.
- checked pump pressure - it's correct (around 5000hPa)
- cleaned the urea tank, filled the tank new adblue and reset level many times by VCDS
- SCR reset by VCDS
- cleaned the injector in ultrasonic cleaner
- cleaned Nox sensor by special cleaning agent for EGR and exhaust systems
- updated the software version in ECU - from 8244 to 8284
- performed test procedures. (Driving 60-90km/h with a constant load for over a kilometer, driving at 100km/h in 3rd, 4th gear for over a kilometer, etc.)
- reductant test by VCDS (where we have to hold the brake and accelerator pedal until the procedure is completed - always end succesfully, but sometimes it takes a second, sometimes more than 6 minutes)

DPF and SCR systems work while driving.

I found that urea quality sensor shows 0.0%. I've read on other forums that users also have 0.0%, but they don't have any error.

I attach below ZIP file with logs.

Maybe someone had similar problem and help me.

Thank you in advance.

[Inmedi]

I add also screenshots from CarScanner Android app. Maybe someone has idea to solve this problem.
Screenshot_20221209-160821.jpgScreenshot_20221209-160830.jpgScreenshot_20221209-160840.jpgScreenshot_20221209-160855.jpgScreenshot_20221209-160901.jpg

[Mario6]

[QUOTE=Inmedi;4452524]I add also screenshots from CarScanner Android app. Maybe someone has idea to solve this problem.

Read. Maybe you'll find help here.

https://forums.ross-tech.com/index.php?threads/22593/

[Inmedi]

Thank you. But I read this forum before and tried these solutions. Without positive effect. I have this problem from above 10.000km. A few mechanics from our region also tried to solve this problem, but they gave up. The authorized service proposes to replace the entire set SCR system with the catalyst and DPF filter... I preferred not to ask about the price. There must be a cause and solution. I hope that this forum people can help to find and solve that problem.

Wysłane z mojego Armor 9 przy użyciu Tapatalka

[kristikapa]

I had 2 customers with same car, same engine, same P204F fault. One ended up replacing everything as dealer said and it was fine, second one ended up deleting the ad blue...

[wbart]

Check adblue ecu. I see more broken in audi

[fuzz1]

Check adblue ecu. I see more broken in audi

Hi
Where is that ecu located? Is it in the tank?

[Inmedi]

I checked adblue ECU by VCDS and ODIS, I can't see any issues (Adblue ECU is located under adblue tank). I disconnected some wires from plug and checked faults - I received clear faults about connection. I downloaded also wiring diagrams from Erwin - it's not equal to my connections.
Do you know where is connected urea quality sensor? Is it integrated with level sensor?
As I wrote before - my urea quality is 0% and raw temperature from urea quality sensor is -273*C. But level sensor and another temperature sensors work well.
Is it possible that catalyst section in exhaust broken?

Wysłane z mojego Armor 9 przy użyciu Tapatalka

[Marcinszpa]

Hi. Did you changed anything in ECU? Some custom map? I had tried many times contact ASO audi, regarding to this error, they are stupid or do not want to let know normal users how to get rid of that problem.
So if you do not have any errors in engine, then you need perform drive cycle. Again, audi will not tell you what is it and how to perform it. That drive cycle is not something you can start in vcds or odis or anything similar.
Take your car for longer trip and try complete all your monitors under engine -> readiness. Once complete without errors you will have your car fully working.

PS. If that is not a physical adblue damage, like not working adblue pomp, then you can reset the miles/km how many times you will need.