The check engine light came on before when traveling down south 3 months ago. The dealer reset the computer, he says, and the light went off. Now the DEF system warning comes on to "take to the dealer max speed 5 mph in 120 miles" along with the check engine light. The dealer here said I used the wrong DEF fluid and will need to change the catalytic converter. And is not covered under warranty, wrong fluid, which is B.S. I told him on the phone to fix it and I will sue him and Chrysler. So he said he would not do the repair and gave the truck back to me. Then I took it to another dealer yesterday with zero miles left before the speed goes to 5 mph. Have to wait and see what this dealer says. When you pay thousands for a vehicle and extend the warranty I expect the problem to be covered by the manufacturer. I did nothing wrong to cause this problem. TBC

Update from Dec 13, 2016: Took to another dealer and the problem with the cat converter was replaced/fixed at no cost to me. Finally it all worked out well.

Happy hunter