Originally Posted by
GMPX
If it's an LMM then the lock will not stop it being flashed over, but it will indeed stop it being read.
With a TechII or EFILive you should be able to flash over the top with another tune, however with HPTuners probably not because their system checks the VIN against the ECM OS and won't proceed if it doesn't get a match, in the case of a EFILive DSP5 OS they won't recognise it.
Also, obviously if you relfash the ECM with a stock tune then you'll loose the DSP functions.