Replacing ECM Module on 2000 Cavalier

Anyone change an ECM Module on a 2000 or newer Cav ?

It's physically easy to do but does the cars computer settings get all screwed up ?

Thanks in advance, Brad

The Powertrain Module is shipped without any flash codes, so if you install the new one it will not function properly. This is because the PCM also fits other platforms and engine and transmission combos. The Dealers charge about 1 hour to do this and it does have to be flashed with a tech 2 scanner.