GM also claimed that with the (I think) C7 corvette. “Encrypted” PCM programming meant it wasn’t possible to reflash, you could only go piggyback, or full stand

GM also claimed that with the (I think) C7 corvette. “Encrypted” PCM programming meant it wasn’t possible to reflash, you could only go piggyback, or full standalone (or engine swap obviously) but you’d lose connectivity with a bunch of other modules. Got worked around relatively quickly, but still.