I have an 09 1500 Silverado with the 6L80. As I understand it the TCM on the 6L80 is inside of the transmission housing. When I ask around I'm told by some I can get a mail order tune and others say I can't. They say the vehicle has to be driven to the shop because of the TCM being inside of the transmission meaning a bench tune isn't possible. Are the 6L80 parameters stored in the ECM which would allow for a mail order tune without having to bring the vehicle into the shop to connect to the DLC or is the TCM idenity contained inside the TCM itself. How do I deal with this problem?