Update. Truck went into dealership yesterday. code was U12B4-00. something along the lines of lost dual battery connection.I am throwing a low voltage code as well. Can you tell me what codes your truck is throwing? My truck goes in Monday. Started throwing code at 172 miles.
notes state "Service manual not helping. tested both batteries, Aux battery fails performance test. replaced Aux battery."
Check engine light is now off. have driven about 20 miles since I had the truck back. no other issues. I hope that was just a small anomaly and we are good to go for many thousands of miles...