Different pcm and theft deterrent I think between 1996 and 2001. Also I think 1996 doesn't use a BCM? If it won't start I would ask the seller of the pcm. He did program it for you to your vehicle SN, right (asked for your vin)? Mine came with instructions on a card to reprogram the theft deterrent. Good luck.

p.s. the service that I used was "Flashmasters"

pps I found instructions that cover the theft deterrent programming for various GM systems after replacing the PCM. It tells you how to ID which system you have. Also note that you will need to have a crank sensor relearn done after replacing the PCM in order for the misfire detection to work correctly.

http://my.cardone.com/techdocs/pt%2077-0011.pdf

I don't have it yet, I was wanting to know what I was getting into first.
Thank you for the information. Very nice.
See ya Les

another question, Is the vehicle driveable before the crankshaft position sensor re-learn?
And after the pcm replacement...
I don't suppose Car Gauge Pro or Dash Command has the re-learn option?
Thanks

Yes, it is perfectly driveable - but expect SES light to be on with the new PCM. Sorry, no crank sensor relearn on the inexpensive software. I do it with HP Tuner's VCM scanner and a laptop. Others report EFI live and Autoenginuity softwares will do it as well. Also as I understand, most Snap on scanners will do crank sensor relearns.