Hyundai Elantra N Owner's Manual page 143

Convenience Features
[1] : Door handle authentication pad
NFC door lock/unlock
You should touch digital key (card key)
to door handle authentication pad (1,
marked position near by the lock button)
door for 2 seconds to lock or unlock the
doors. If the Two Press Unlock feature
is applied (press twice for unlocking),
touching the digital key (card key). In this
state, if you touch one more time within
4 seconds, all the doors unlock.
5-22
Inoperable condition
If you do not touch the digital key (card
key) to the center of the door handle
authentication pad accurately. it may not
work. In addition, if you overlap and use
the key with NFC-enabled cards such as
transportation card or credit card, it may
not work.
Note that if you try to lock your vehicle
with digital key (card key) in following
cases, the doors will not be locked and
OCN7050128
chime will sound for 3 seconds.
The Smart Key is in the vehicle.
The POWER button is in ACC or ON
position.
Any of the doors, hood or trunk are
open
If the digital key (card key) does not work,
please move the card 4 inches (0.1m)
away from the handle authentication
pad and retry to touch. If the card key is
damaged by impact, it may not operate
properly or at all. You should buy a new
card and register again. Long-time
exposure to high temperature may cause
the card key to malfunction. Please be
careful not to expose the key to direct
sunlight or high temperature.