i have an 03 GMC 2500hd with the 6.0L. The previous owner had a hypertech installed in it and it locked the ecu on him. he took it to the dealership and had it flashed. I now own it and tried to install my superchips and the code Lost Communications, error num 002 came up just as it started saving stock. i have heard about hooking battery charger up because it may not have enough voltage so i did and another code popped at the same time. it was upload fail error num 040. i dont know what to do.