gotta love those specific codes...P0700** Transmission Control System Malfunction
What type of transmission do you have? manual or auto?
that pertains to the fact that the 6-speed Allison would actually overheat while the truck idled, a solenoid wouldnt open and allow the oil to circulate inside the trans, and even at sub zero temps the allison would burn up, there is a reflash for that, it opens said solenoid keeping the tranny coolgotta love those specific codes...
I read somewhere that GM has an update on the allison for trucks that operate in cold weather alot...not sure if this would help you...also..might wanna post this in the Dmax area.