This key contains an embedded micro-chip called a transponder. Each transponder has its own unique code--it's the key's 'fingerprint'. ... If the car's receiver recognizes the code, it will allow the car to start.
How do you program a Hyundai Sonata key?
Stick the key to your Hyundai into the vehicle's ignition cylinder. Turn the key to the "ACC" or "Accessory" ignition position. Hold down the "Open" or "Unlock" button on the keyless entry FOB until the vehicle's lights flash. The keyless entry FOB is now reprogrammed to your Hyundai vehicle.
Can I drive my Hyundai without a key?
You need the FOB to start the car but once it is started the car will drive and operate normally with or without the key in range. Once the car is shut off you will need the key to restart it however, so going anywhere without the key is a one way trip.Oct 3, 2009