[Zak]

Don't know if you got to the bottom of this, but your def pump froze. Exact same thing and observations when mine went at slightly colder temps three weeks later than yours. My buddy is the cummins tech at the dealer and he said dozens of 2016s came in during January....all with failed def pumps. Hope yours is ok...maybe have them check the codes in case it's a bad one and get replaced while under warranty.