I have a 2014 with the 2.1 (18,000 miles), we purchased about 2 weeks ago, and twice now we have taken it in for the dreaded Low DEF fluid warning, then the 10 starts remaining countdown. Both times I have taken it to the dealership to have it reset. They told me if it does it again they will dig into it more. That day has come (1 week after the last time), I have it going in for a scheduled service B tomorrow. What is going on here? The tank is completely full, and yet the sensor believes it's on empty or near to it. The funny thing is, the last two times this happened, the dealer reset the counter and it was fine for 5-7 days before the warning came up again. If it was a bad level sensor, I would think it would be bad all the time? I should know more tomorrow when it goes in for routine service, but if anyone out there has any ideas or things I should ask the service guy, please let me know. I don't think the sprinter dealer here is trying to skirt the issue, they seem like a good group of guys and have been nothing but awesome so far. This is under warranty, so no issues with costs to me, just want to get this working 100% so we don't get stranded out of town with a countdown timer.