tech2 nor our software modifies the ECM serial # during a reflash.
if you write entire with a file with operating system that is not compatible with the existing operating system, it can corrupt the serial # and other things including making the PCM unreadable/writeable.
tech 2 flashif you write entire with a file with operating system that is not compatible with the existing operating system, it can corrupt the serial # and other things including making the PCM unreadable/writeable.
Generally this happens if you write a much newer or much older OS to the ECM.
