disable radar detector.
does he have an alarm? or anything tied into the elec. ystem or obd port?
Wes' LLY had an alarm and it was taped right into the back of the obd port. wouldnt take a tune, would freeze up until we disconnected that wire.
disable all that and then try a normal flash again. A full flash prolly wont work if you freeze up in the middle of a normal flash...
Like mike said disable it all,Just to be certain. Close the door with windows down Even make sure the head lights wont come on. All these step are just precautionary but i would do them in your situation.
I have full flashed my truck hundereds of time with no issues but every once in a while it happens
your computer is fully charged or plugged in and no other programs running?
Ive seen command starts and do funky things also,Is your cig lighter working?
Have you followed the steps in the instructions to a T?