Just because you don't have smartkey doesn't mean you don't have the alarm enabled.
A dealer can enable the alarm, but may instead try and sell you the alarm package. He is supposed to do that. They can use the scanner, go to Option Setup, then DOP Security, ON.
As long as they don't install GBS, DOP Security will be an option they can turn on.
If they do install GBS, then they have to remove or cut a specific wire to the Body ECU.