Update on mine - tailgate module and body control module were both bad. Both were replaced under warranty this morning. A good experience with Hendrick CDJR in Concord NC if anyone in the area happens to stumble upon this post. I had to leave the truck overnight for initial diagnostics, and overnight again yesterday once the tailgate module was swapped and it was discovered the BCM was bad. All the loaners were out both times, but they booked Uber's to and from the dealer / home so I didn't have to worry.