So you have the right idea, unfortunately this vehicle is a bit unique. This is because the Body Control Module is responsable for unlocking the doors AND receiving the RKE key fob commands so there is no reason for there to be a CAN BUS message to control the locks on this using the RKE messages. So don't bother with pressing the key fob and trying to find a command to replicate, this won't work.
HOWEVER, OnStar has a message it sends to control the locks. So you can simply watch for that message:
Unlock Drivers Door is: 0x1024E097 00 02 FF
Unlock All Doors is: 0x1024E097 00 03 FF
Lock All Doors is: 0x1024E097 00 01 FF
If you are going to do an Unlock or Lock from a Sleeping bus you will need to send a High Voltage Wakeup and a VNMF Frame (0x641 01 FF FF FF FF FF FF FF will work)
And if you need to turn on your heated seats try this sequence:
0x102A0099 04 (Send multiple times to simulate multiple heated seat button hits)
delay 100 ms
0x102A0099 00 (Send this to simulate release of the button)
Want to remote start your car (works only if you have a factory remote start installed and enabled), send this sequence:
0x1024E097 80 01 FF
delay 200ms
0x1024E097 00 00 FF
and Cancel Remote start with:
0x1024E097 40 00 FF
delay 200ms
0x1024E097 00 00 FF