Got a 2003 with one key and one FOB. I had a second fob from a Buick that I thought might work, so I followed the programming where you hold the unlock button, hit ignition twice. The original fob made the doors lock/unlock, so I assumed it took the reprogram. The Buick fob didn't get any response. So I closed out the programming by turning the key on. But now my original fob doesn't work at all. I went back and did the programming process again, this time just getting the original fob programmed. The Tahoe responded to the fob during programming again. However, afterwards the fob just doesn't work at all. So is it a problem with the original fob, or do you have to have two good fobs to get the programming to work, or did I hose something else up? Thanks in advance for your help.