If you don't let them run long enough or drive far enough the def tank is froze after -12 or so and it messes the system up. Then you have to put it inside and warm it up and go for a drive to reset it. Happened 3 times last winter to me twice it went back to dealer last time I just put it inside the shop for 4 days.So what kind of def problems do these trucks have??
I just bought a 2015 and I'm curious how the def system works in the winter.