There are unique identifiers in the two key FOBs that come with the truck, one is assigned #1 and the other is assigned #2. Older GMC models had physical number on the FOBs , like my 2006 Yukon Denali, but these do not. You can tell the difference however when you get in the truck and press...
1) Display remaining battery capacity in percentage while truck is on
2) Allow PAK (Phone As Key)
3) Allow a button on the steering wheel to pause audio playback
4) Allow EA (Electrify America) activation in the app?
1. If you match your remote # to the memory setting # on the door the seat will automatically move to the correct position by detecting the remote. I had them mismatched at first. There is an "easy entry" setting too.