The local auto parts store usually will do it for free (AutoZone, Napa, etc).
All of the reports we've had here usually has the light come on for a little bit, then go off and not return. Hopefully it's nothing to crazy for you!
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Welcome Craig! Share some picture if you have some, we love pictures! :D
Short Answer: Regen is simply the truck burning out the "trapped soot" in the diesel particulate filter (DPF).
Long Answer: https://en.wikipedia.org/wiki/Diesel_particulate_filter
How many miles? Technically they could say that's a wear item.. but what on a vehicle is not? If it's a decent dealer they should replace them for you.
I've never done it..but my dad has 3 times! I just drained the tank each time and put a new fuel filter in it. Also added the power service diesel treatment from walmart and no problems yet. The last time has been about two years ago.
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