First time fiddling with HP tuners, was going to install some gears and a posi this weekend and wanted to get a feel for flashing, etc. 2007 4.8l 4l80e new body style sierra. Pulled my stock file a few months back, just updated it today with a new tire size and wrote the config. Write was successful but I have no start/crank. No power windows or radio turning on. I wrote back the original config file and it was successful, still same result. When I scan the truck and pull codes all I see is U0140 loss of comm with body control module (pending). I'm hoping nothing is fried as I can still flash/connect to the ECM/TCM.
I did some reading and saw some recommend pulling the negative battery terminal and waiting for some time but any other insight would be helpful. Tunes are attached but not too much to them.