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Continue ShoppingBy R&D
Published on June 10th, 2026
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The Smart Key system in the 2016 Hyundai Elantra L4 1.8L is designed to provide enhanced convenience and security for drivers. This feature allows keyless entry and engine start, enabling you to unlock the doors and start your vehicle without removing the key fob from your pocket or bag. Understanding and properly using the Smart Key system can greatly enhance the ease and enjoyment of your driving experience. This guide provides an overview of the Smart Key system and instructions for its efficient use in your 2016 Hyundai Elantra L4 1.8L.

Your Hyundai is equipped with a Smart Key, which allows you to lock or unlock the doors (and trunk) and start the engine.
1. Door Lock
2. Door Unlock
3. Trunk Unlock
4. Panic Alarm

To lock the doors:
1. Ensure all doors, the engine hood, and the trunk are fully closed.
2. Press the door handle button or the Door Lock button (1) on the Smart Key.
3. The hazard warning lights flash, and the chime sounds once.
4. Confirm that the doors are locked by checking the position of the door lock button inside the vehicle.
NOTE: The door handle button will function only when the Smart Key is within 28–40 inches (0.7–1 meter) of the exterior door handle.
To unlock the door on driver’s side:
1. Carry the Smart Key with you.
2. Press the door handle button or the Door Unlock button (2) on the Smart Key.
3. The driver’s door unlocks, the hazard warning lights flash, and the chime sounds twice.
4. Press the Door Unlock button again within four seconds to unlock all the doors.

Notice:
To unlock the door on passenger’s side:
1. Keep the Smart Key with you.
2. Press the door handle button or the Door Unlock button (2) on the Smart Key.
3. The doors unlock, the hazard warning lights flash, and the chime sounds twice.

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To unlock the trunk:
1. Keep the Smart Key with you.
2. Press the trunk handle button or the Trunk Unlock button (3) on the Smart Key for more than one second.
3. The hazard warning lights flash twice. Once the trunk is opened and closed, it automatically locks.
Notice: Once the trunk is unlocked, it automatically locks after 30 seconds unless the trunk is opened.
Hold the Panic button (4) for more than one second. The horn sound,s and the hazard warning lights flash for approximately 30 seconds.
To exit panic mode, press any button on the Smart Key.
When the ENGINE START/STOP button is in the ACC or ON position and any door is open, the system will check for the Smart Key.
The indicator light blinks when the Smart Key is not in the vehicle, and any door is open with the ignition switch or Engine Start/Stop button in the ACC or ON position. If you close all doors, the chime sounds for approximately 5 seconds. The indicator turns off once the vehicle is in motion.
Caution:
If the Smart Key is not functioning properly, you can lock or unlock the door using the mechanical key.







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