Have a 2015 Pete 389 that randomly throws spn168-fmi13 battery potential/power input 1 out of calibration, I believe it has something to do with the cab controller. Only items not currently working are interior lights, all fuses check out and truck has new batteries and charging normally. Anyone ever have this code and pin pointed the issue. It won’t let me clear the code and have tried leaving batteries unhooked for a long period to try a reset but no luck.