Viper 791XV system not programming new remote
 

I have a Viper 791XV system I got from a friend that they ripped out of their car. I have it hooked up on my bench and I can get the remote and the unit into programming mode, but the remote doesn't program to the unit.

I have followed the instructions in the manual exactly as it said, and I still get nothing
Anyone here has any things to try or have any experience with this system or something similar?

TIA