To unlock:
1. Carry the smart key.
2. Either press the tailgate handle button or press the Tailgate Unlock button (3) on the smart key for more than one second.
3. The hazard warning lights will blink two times.
Information
Hyundai Kona (OS) 2018-2023 Service Manual: Lumber Support Units Repair procedures
Removal
1.
Disconnect the negative (-) battery terminal.
2.
Remove the front seat assembly.
(Refer to Body - "Front Seat Assembly")
3.
Remove the seat back.
...
Hyundai Kona (OS) 2018-2023 Owners Manual: Limitations of the system
The driver must be cautious in the below situations, because the system may not
detect other vehicles or objects in certain circumstances.
When a trailer or carrier is installed.
The vehicle drives in inclement weather such as heavy rain or snow.
The sensor is polluted with rain, snow, mud, etc ...