Some vehicles are equipped with a deadlock system. Deadlocks prevent opening of a door from either inside or outside the vehicle once the deadlocks have been activated providing an additional measure of vehicle security.
To lock the vehicle using the deadlock function, the doors must be locked by using the remote key or smart key. To unlock the vehicle, the transmitter or smart key must be used again.
WARNING
Do not lock the doors with the remote key or the smart key with anybody left in the vehicle. The passenger in the vehicle cannot unlock the doors with the door lock button. For example, if the door is locked with the remote key, the passenger in the vehicle cannot unlock the door without the transmitter.
Hyundai Kona (OS) 2018-2025 Service Manual: Rear Door Window Glass Repair procedures
Replacement
1.
Remove the rear door trim.
(Refer to Rear Door - "Rear Door Trim")
2.
After loosening the mounting screws, remove the Rear door full handle
mounting support (A).
3.
...
Hyundai Kona (OS) 2018-2025 Owners Manual: Smart key precautions
The smart key may not work if any of the following occur:
The smart key is close to a radio transmitter such as a radio station
or an airport which can interfere with normal operation of the transmitter.
The smart key is near a mobile two way radio system or a cellular phone.
Another vehicle†...