I have a 2012 Silverado that apparently has a malfunctioning climate control module (GM 20921714) according to the local Chevy dealer. Since the part is discontinued, they said that if I found a used one, they could install it for me...labor charge. So I eventually found one...took some looking. My question...is this plug and play whereby I can do the installation myself (just unhook the old one and put the other one in), or does this require some calibration/diagnostics/etc that I'd need to have the dealership do.