I contacted both the dealer and commercial customer services. There was a lot of back and forth with finger pointing, customer service essentially said "the onus falls on the dealer", and the dealer clarified the whole EPA weight classification. Each time they checked "the system" they couldn't find any warranty for my specific vehicle(2012 3500 HD S) where this was covered. That said after making a small trek recently totaling 400 miles, the check engine light has gone out. I'm taking it to my local shop this week to validate the status(yes I can check the OBD-II myself but I've got a good relationship with my shop) so we'll see what's up, hopefully good news.