
Your HYUNDAI uses a Smart Key, which you can use to lock or unlock a door (and trunk) and even start the engine.
1. Door Lock
2. Door Unlock
3. Trunk Open
4. Panic
Locking

To lock :
1. Close all doors, engine hood and trunk.
2. Either press the door handle button or press the Door Lock button (1) on the smart key.
3. The hazard warning lights will blink and the chime will sound once.
4. Make sure the doors are locked by checking the position of the door lock button inside the vehicle.
Information
The door handle button will only operate when the smart key is within 28~40 inches (0.7~1 m) from the outside door handle.
Even though you press the outside door handle button, the doors will not lock and the chime will sound for three seconds if any of the following occur:
WARNING
Do not leave the Smart Key in your vehicle with unsupervised children. Unattended children could press the Engine Start/ Stop button and may operate power windows or other controls, or even make the vehicle move, which could result in serious injury or death.
Unlocking

To unlock:
1. Carry the Smart Key.
2. Either press the driver's outside door handle button or press the Door Unlock button (2) on the smart key.
3. The driver's door will unlock. The hazard warning lights will blink two times.
If you press the driver's outside door handle button or Door Unlock button on the smart key again within four seconds, then all the doors will unlock.
Information
Trunk opening
To open:
1. Carry the smart key.
2. Either press the trunk handle button or press and hold the Trunk Unlock button (3) on the smart key for more than one second.
3. The hazard warning lights will blink two times.
Once the trunk is opened and then closed, the trunk will lock automatically.
Information
The trunk handle button will only operate when the smart key is within 28 inches (0.7 m) from the trunk handle.
Panic button
Press the Panic button (4) and hold for more than one second. The horn sounds and hazard warning lights blink for about 30 seconds. To cancel the panic mode, press any button on the Smart Key.
Battery replacement
Start-upHyundai Sonata LF 2014-2019 Service Manual: Smart Key Repair procedures
Smart Key
Smart Key Code Saving
1.
Connect the DLC cable of GDS to the data link connector (16 pins) in driver side crash pad lower panel, turn the power on GDS.
2.
Select the vehicle model and then do "Smart Key Code Saving".
3.
After selecting "Smart Key Teaching" menu, push "ENTER" k ...
Hyundai Sonata LF 2014-2019 Service Manual: Troubleshooting
Trouble Symptom Charts
Trouble Symptom 1
Trouble Symptom 2
Trouble symptomProbable causeRemedyThe set vehicle speed varies greatly upward or downward"Surging" (repeated alternating acceleration and deceleration) occurs after settingMalfunction of the vehicle speed sensor circuitRepair the ...