low battery voltage can and has caused me to end up in limp mode, shut the truck down, disconnect the batteries for 20min, reconnect them and see what happens. The low voltage is a combination of the cold and possible weak batteries, between your glow plugs and intake heater it really sucks them down. Turning on the heated seats and defrost when you start up only makes the problem worse. The TCM freaks out. I've had it happen once this year (it was -20F) truck would go into gear but only 5th, barely any useable power in reverse, I could barely back away from the curb going downhill.
2008 2500HD LTZ, EFI Live- Idaho Rob's Tunes, 4" Magnaflow Turbo Back, Raptor 150 Lift Pump, Transgo Jr, All Season Diesel EGR delete with high flow Y-bridge, Edge Insight for gauges,