You have a Canadian model or a fleet model? Most of these trucks come with it turned off by default
Anyways, theres 2 decent options. You can take it to a dealership and they may be able to change it. They may also charge you for "labor" depending on how nice they're feeling. I say "Labor" cuz all they do is sit there and push buttons on a big fat computer. Doesn't really justify the labor charge but it is what it is
The second option is AlfaOBD. It can do almost everything the dealer can do, and in some cases more.
Here's the thread. Overall it can cost over $100 bucks but imo its well worth it if you're in to changing options on your truck