** update **
Service manager called me this morning to give me a progress report,
they traced the fuel transfer lock out, to the BCM (body control modual) seeing a pressure loss in fuel system. they couldnt reproduce the pressure loss until they started to pull back and forth on on of the tubes connected to the tank. they pulled all the tubes that cross connect the tanks and inspected them and they are fine, and pulled the right tank to inspect where the tubes connect and it is fine/aligned correctly. apparently most of the lines and fuel system are plastic, that i didnt know. they are replacing every line in the system regardless if they seem fine or not. they are having them pulled from the assembly line at the factory, and put through the QC check (i guess GM ranbomly QC checks ever couple hundred to see if there are any production variations outside of the acceptable tolerences) before over nighting them to the dealership.
they know that they are in the approximate area of the problem, but not sure exactly what it is. atleast they are replacing all of the parts at once instead of throwing 1 part at a time at the problem.
so as it stands now, i just gotta wait for UPS to do their thing.
glad they are do what i asked of them, which was to fill me in on every technical detail of how they are troubleshooting and what steps they are taking, so i can put my mind at ease, and not treat me like someone "who only understands put gas and oil in the car and go"