Happened last night at least 4 times. All doors, windows, trunk and hood were securely locked. I ultimately decided to disconnect the battery for the night. Re-connected it this morning and used my 2nd key FOB to lock the car afterwards. Since doing this it hasn't gone off once today. I don't know if switching key FOBs did the trick or what. My old Elantra had this same problem and it was the hood switch starting to act up. I would just open the hood and slam it shut real good and it would stop the issue for a while. Maybe opening/closing the hood when I disconnected and reconnected the battery jarred the sensor back into place...? How can I verify if the hood sensor is actually bad?

 

You can try unplugging it and see what happens?