This is the worst review that I have seen so far on the Titan diesel. I hope that it is an isolated case: http://www.caranddriver.com/reviews/2016-nissan-titan-xd-long-term-test-review
I just googled up the truck and several sites with owners report several issues with DPF systems, transmission issues, reflash issues, dealer tech issues, ect. Sounds like some of these trucks have first production issues maybe more. Hopefully the dealers and or Nissan took a page from Fords issues with rolling out the new back then 6.0 and won't repeat the same.