2024 Hyundai Sonata Key Replacement

The 2024–2025 Sonata uses the same key setup, so everything on this page applies to those years too. The full picture is on the Hyundai Sonata key guide.

2024 Hyundai Sonata: key facts

Key type: Smart / proximity key
Push-to-start: Yes
Transponder chip: 4A (Hitag AES)
Programming: OBD
All keys lost: We can originate new keys on site

Facelifted DN8: fobs move to Hitag-AES 4A (TQ8-FOB-4F89U44). Aftermarket tools report good 4A coverage, but all-keys-lost support is still maturing — confirmed per job.

What kind of key does the 2024 Sonata use?

The 2024 Sonata is the facelifted DN8, and it comes with a smart proximity fob. You carry it in a pocket, press the brake and push the start button; nothing is turned in an ignition. Inside is a 4A chip in the Hitag AES family. Hyundai moved its fobs to Hitag AES with this facelift, and the part number we see for it is TQ8-FOB-4F89U44. Two supplier references, uhs-hardware.com and bestkeysupply.com, agree on the chip.

For you, that means the fob has to be programmed to the car before it will start it, and that programming is done through the OBD port. A blank from a parts counter or an online listing is only a starting point. The fob also holds a mechanical backup blade, which matters more than most owners expect.

What does 'key not detected' mean on this car?

It is the most common complaint on this setup, and it usually points to a dead fob battery. The dash reports 'key not detected,' but the emergency blade still opens the door, so you are not locked out. Slide the blade out of the fob, open the door with it, and replace the battery before assuming the fob has failed.

The other two things owners bring us are worn fob buttons and cracked shells. Whether a shell can be saved or the fob should be replaced depends on its condition, and we look at it in person before recommending either.

Spare key or all keys lost: how does it work here?

Duplication on this car needs an original key. If you still have one working fob, a spare is the simpler job: we program the new fob through the OBD port and check that it works.

All keys lost is possible, but it is a different job. Aftermarket tools report good 4A coverage, yet all-keys-lost support is still maturing, so we confirm it per job rather than assume. If your car turns out to be a dealer-only case, we will tell you plainly.

Call (213) 577-1366 and tell us the model year, whether any fob still works, and where the car is parked.
We confirm your VIN and fob type before anything is ordered or programmed.
We come to the car in a mobile van, or you bring it to our Westwood storefront if it can be driven.
We program the fob through OBD, then check that it starts the car and the blade opens the door.

What affects the price of a 2024 Sonata key?

We don't put numbers on a web page, because the honest answer depends on your situation. A smart fob costs more than a bladed key, and replacing a lost fob costs more again, since all keys lost needs professional programming. What moves the quote:

Whether you still have a working fob. A spare made from an existing key is usually the more economical route.
How many fobs you need programmed.
The condition of your current fob, shell and buttons.
Whether we travel to the car or you come to the storefront.
What the VIN check shows about tool support for your specific car.

Locked out or need a locksmith now?

We answer around the clock, every day of the year.

Call (213) 577-1366

Why call Wilshire Lock & Key for this?

We have been in business since 1987, with a storefront at 10740 Wilshire Blvd in Westwood and mobile vans serving 140 cities across Los Angeles and Ventura counties. It is one company with no dispatch middlemen between you and the technician, and David, our owner and lead technician, oversees the work. The phone is answered 24 hours a day, every day.

California requires locksmith companies to hold a BSIS LCO license, so ask any locksmith for theirs before they touch your car. For more on these cars, see our Hyundai key guide or the Sonata overview, or contact us with your VIN.

Frequently asked questions

Does the 2024 Sonata have a transponder chip?

Yes. The smart fob carries a 4A chip in the Hitag AES family. The car's immobilizer must recognize it, which is why programming is required.

Can you make a spare if I only have one fob?

Yes. This car needs an original key for duplication, and we program the new fob through the OBD port.

Can you make a key if I've lost every fob?

It is possible, but all-keys-lost support for this facelift is still maturing in aftermarket tools. We confirm by VIN before committing, and we'll say so if the job turns out to be dealer-only.

My dash says 'key not detected.' Do I need a new fob?

Probably not yet. A dead battery is the usual cause. Use the emergency blade to open the door and replace the battery first; if the message stays, call us.

Is there a regular metal key in the fob?

Yes, a mechanical backup blade. It opens the door when the fob battery is dead, but starting the car still relies on the fob.

Will a fob I bought online work?

It might, but send us the part number first. This facelift uses Hitag AES 4A fobs, so a fob built for an older setup may not work. We confirm compatibility before programming.

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Reviewed by David, Owner & Lead Technician, Wilshire Lock & Key — in the locksmith trade since 1987.

Last updated 2026-10-11.