Keyless entry trouble

[lo2doorho]

99 2 door Tahoe 2wd with factory keyless entry. Had 2 key fobs but only one worked. I changed the battery in the one that didn't work and tried to program it according to the manual with the 8 and 4 pin on the OBD2 port. After attempting this neither one of my key fobs will work now and I've tried multiple times to program them with no success. Has anyone else had a problem like this I've searched throughout the forum and could not find any info on this particular problem with programming the key fobs. Also does having an aftermarket radio affect programming the key fobs.

 

[GoToGuy]

There's multiple threads with advice on this.