Dreaded AdBlue issues

[ian.f]

Car went in to the garage to have suspension failure sorted, day after I get it back engine light comes on ‍
Codes are:

P06B1 - sensor power supply “A” circuit low
P20E8 - reluctant pressure too low

So great, AdBlue issues now!
I’ve filled up the tank, and in my first drive today, I get a warning that the tank needs re-filling and 650 miles left.

Seems to me this could be a control module issue?
I’m really loathed to have to buy a new AdBlue system and add another 1.5k on to the spend of the car.
Before I do, can anyone lend any experience of this issue?
Can I replace the control module? Would it need coding afterwards?
Thanks guys.

 

[ian.f]

So after A LOT of research today, I’m utterly confused and there doesn’t seem to be an answer as to what the exact issue is. Short of replacing everything at a juicy cost of over £2k.

I’ve seen some threads out there that suggest the injector is the issue. The injector gets clogged and doesn’t deliver reductant in high enough volumes, thus making the sensor post-dpf trigger a warning as the exhaust gasses aren’t reduced to within operating parameters.
Sounds logical, so I’m going to have a go at cleaning it over the weekend.

I’m wondering about the 650mile warning though, as that would be tank/filler/float related.
I’ll find that out shortly though as I have a 400mile journey to make to get home.

Something tells me I’m going to be sat on the motorway tomorrow with my hazards on…looking at one hell of a bill.

**sighs**

 

[ian.f]

Well I made it back with 10mikes to spare.
Tried to clean the injector but it was spotless! Too clean in fact.
So on to ringing around garages to take the hit.

 

[ian.f]

Ok, so ringing around (main dealer, indy-specialists, indys) it appears that nobody’s actually interested in doing a full diagnosis. Each one said the full system needs replacing.
Am I the only one that finds this insane? There are multiple components in play; sensors, injector, pump, control unit…so why can’t/won’t the industry troubleshoot the problem?
Madness.

I’ve found a guy who might be able custom-code the “no restart” code, out of the ECU…so am investigating that to buy me some time!!

If anybody from Audi reads this thread; you should be looking to resolve/enhance the fault dignosis here. It’s shocking that your customers have this amount of stress and work to do to keep your motors on the road. Vorsprung durch technik my ****!

 

[Sibmets]

I had an Adblue fault and as I read from manual - the remaining miles doesn't indicate the problem You have, that's just there to make You fix it - With proper diagnostic tool (VCDS/obd11) You can reset the counter.
I had a fault - P21CA00 - Reductant Control Module Supply Voltage Circuit static. Audi dealer pointed to AdBlue control module (#4M0907355D) as faulty. It cost me 300€ approximately a year ago.
About replacing whole system - if the pump itself dies, then the whole system is replaced, as the new pump has different dimensions and doesn't fit in the old tank - that's what I read somewhere.

Sent from my Pixel 6a using Tapatalk

 

[ian.f]

I’ve now spoken to a gent called Andy @ ECUFlash.co (yes, it’s .co).
He’s sorted me with coding out the “no restart” fault from my ECU. So I still have the reductant error codes in the ECU, but I don’t have the forced “no restart” errors flashing up. The AdBlue system is still in working order, so it’s totally legal.
This is great as I can get the actual fault diagnosed and sorted, rather than just be forced to have a new system.
I’d recommend Andy to anyone who wants to get rid of the AdBlue force restart. Keeps the car going and keeps it legal.

As far as the actual fault on the system goes, I’m still none the wiser.
I’m going to test the system out in the next week or so.
I do think it might be the tank sensor causing the fault, as I read the tank level in Carista which read 0. But I know for a fact there’s AdBlue in there. I’ve read that the tank level is measured by ultra-sonic sensors that measure the amount of air in the tank and calculate from there, so it may be that the tank is too full and thus giving an error. I’m going to drain a bit and see how we go.

Onwards with no worries about restarting!!

 

[ian.f]

I had an Adblue fault and as I read from manual - the remaining miles doesn't indicate the problem You have, that's just there to make You fix it - With proper diagnostic tool (VCDS/obd11) You can reset the counter.

Indeed, but I don’t believe the counter can be reset, can it?
I haven’t found anyone that was able to do that. Did you have it done?

 

[Sibmets]

I did it using obd11 and just deleting the fault codes. They came straight back with again with the interval it first appeared.

Sent from my Pixel 6a using Tapatalk

 

[ian.f]

I did it using obd11 and just deleting the fault codes. They came straight back with again with the interval it first appeared.

Sent from my Pixel 6a using Tapatalk

Sounds like we have different issues as no matter what codes I removed, the count down continued.
Will wait to see what my troubleshooting finds!