If the remote key is not working properly, try replacing the battery with a new one.

Battery Type: CR2032
To replace the battery:
1. Insert a slim tool into the slot and gently pry open the cover.
2. Using a screw driver, remove the battery cover.
3. Remove the old battery and insert a new battery. Make sure the battery position is correct.
4. Reinstall the battery cover and key cover in the reverse order of removal.
If you suspect your remote key might have sustained some damage, or you feel your remote key is not working correctly, it is recommended that you contact a HYUNDAI authorised repairer.
Information
An inappropriately disposed battery can be harmful to the environment and human health. Dispose of the battery according to your local law(s) or regulations.
The remote key will not work if any of the following occur: The key is in the ignition switch. You exceed the operating distance limit (about 30 m [90 feet]).
Your HYUNDAI uses a Smart Key, which you can use to lock or unlock a door (and tailgate) and even start the engine. 1. Door Lock 2. Door Unlock 3.
1. Position the vehicles close enough that the jumper cables will reach, but do not allow the vehicles to touch. 2. Avoid fans or any moving parts in the engine compartment at all times, even when the vehicles are turned off. 3. Turn off all electrical devices such as radios, lights, air conditioning, etc.
Load and speed capacity tyres *1 LI : LOAD INDEX *2 SS : SPEED SYMBOL Air conditioning system Contact a HYUNDAI authorised repairer for more details. Vehicle weight and luggage volume M/T : Manual transmission A/T : Automatic transmission DCT : Dual clutch transmission Min : Behind rear seat to upper edge of the seat back.