2000 jimmy wont reprogram

Hi I am redoing a stolen recovery truck. I am at the point of reprogramming the computer. I have done the 30 minute pass lock reprogramming steps but it doesn't seem to be working. Now my security light stays on all the time and my scanner will not read it anymore.

Any suggestions or advice would be greatly appreciated.

Dennis

Sounds Like you lock yourself out. A little feature GM has. You may need the dealer to unlock it.