Originally Posted by fullmetaljacket

Sorry, Did not want to start a new thread on DEF. Just got warning messages level 2 (200 miles to go) with no level 1 (999 miles to go). Plus the warning message...

"Incorrect diesel exhaust fluid added. Please note the remaining driving range! if driving range reaches 0 miles/ kilometers, engne start will not be possible. Have the system checked by the nearest BMW center".

My initial guess was a low DEF level so I did a a DEF refill/top up. Both active and passive tanks drank around 17 liters (One 10 liter jug and 70% of another 10 liter jug of BMW AdBlue DEF).

The warning messages did not disappear! :-( So I did 2 scans: Foxwell NT510 and Carly. I was able to get identical error messages which could not be erased/ cleared...

0041F9
DeNOx system, plausibility

00474C
DeNOx system, warning and Abschaltszenario

004748
DeNOx system, warning and Abschaltszenario

I did a quick research on this issue from various forums and found out that this might be a NOX sensor related issue and not a DEF level issue since the sensor inside the DEF tanks only measures DEF level and they do not determine whether the DEF is good or bad quality. I'm going to the a BMW certified shop this weekend to have this checked since I only have 188 Kilometers left. I'm just soliciting thoughts, information or comments you might have regarding my theory before I go to the shop.