Ambient temp is about -20f and our check engine light is on now with these two codes. Some googling shows that this is related to the dpf Regen not making sufficient progress. Is this normal due to the temps or is something actually wrong with the truck? In 1500 approx miles on our trip it's done at least two passive regens (you can hear the noise and mpg goes down) but no active regens (will display message in truck). Thanks all for your input.