If the Smart Key does not operate normally, you can lock or unlock the door by using the mechanical key.

Move the release lever in the direction of the arrow (1) and then remove the mechanical key (2). Insert the mechanical key into the key hole on the door.
To reinstall the mechanical key, put the key into the hole and push it until a click sound is heard.
Start-up
Loss of a smart keyHyundai Kona (OS) 2018-2026 Service Manual: Front Hub / Knuckle / Tone Wheel Repair procedures
Removal
1.
Loosen the wheel nuts slightly.
Raise the vehicle, and make sure it is securely supported.
2.
Remove the front wheel and tire (A) from the front hub.
Tightening torque :
107.9 - 12 ...
Hyundai Kona (OS) 2018-2026 Service Manual: Brake Booster Repair procedures
Brake Booster Operating
Test
For simple checking of the brake booster operation, carry out the following
tests.
1.
Run the engine for one or two minutes, and then stop it. If the pedal
depresses fully the first time but gradually becomes higher when d ...