I used some Info I fould floating around here On how to add a transmitter to a 97 Bonneville SSE. It involved jumpering pin 4 to 8 or somthing similar to that on the OBDII service port. This made the locks lock and I then pressed a button on each of the remotes including the new one, pulled the jumper and turned the ignition off. The new remote I bought works great but I cant get the old two to work anymore. I repeated the pin jump and tryed to learn them several times but had no luck. Is there a step I am missing or a trick to this. Before I started both the old remotes worked but the one had a the contact pads worn out and had press a few times to get it to work. I bought a new one on ebay with all the same ID numbers on back, So the way I saw It i'd just relearn the one old one and the new one and call it a day. Any help would be appreciated, I'd kinda like to have two working remotes again.

Thanks

Dan

From the1997 Factory Service Manual.
I have used this with the same situation as you have and it worked for me.

1 Turn ignition switch "off"
2 Jumper DLC pin 8 to pin 4 Close all doors.
3 Turn ignition switch "on" Door locks cycle.
4 Press and hold lock and unlock buttons on one transmitter. After a 30 second delay the doors will lock and unlock.
5 To program extra transmitters, repeat step 4. Do not turn off ignition. If ignition is turned off the first transmitter will become inoperative.
6 Disconnect jumper from DLC

Hope this helps.