South Korean police book 80 Tesla owners for illegally unlocking FSD with aftermarket devices

South Korean police have booked 80 people for using aftermarket devices to switch on Tesla's Full Self-Driving (Supervised) in cars that are not allowed to run it in the country. The Seoul Metropolitan Police Agency announced the case on Tuesday, October 27, and said officers seized 21 of the devices. According to Drive Tesla, the suspects have been referred to prosecutors. It is one of the largest crackdowns so far on FSD "jailbreak" hardware, which has spread in Korea, China and Europe over the past year. The software is already in these cars, and many owners paid for it.

What exactly did the suspects do?

They bought or built boxes that get around Tesla's regional lock. According to reporting by Korea JoongAng Daily, cited by Electrek, some of the suspects bought unlock modules from Europe or China, while others built their own. One person fitted a European-made unit to his own Tesla. An IT worker put together a device using information he found on GitHub. Suspects also swapped tips online on how to unlock FSD and how to stop the car from logging that it had been activated.

The modules are small plug-in boxes that connect to the car's internal CAN bus and get around the regional software lock. They work because the hardware in Korean Teslas is the same as in markets where FSD is enabled. Earlier this year such devices were reported to sell for around €500.

Why is it illegal in Korea?

Because it is an unauthorized change that can affect safety. The case falls under South Korea's Motor Vehicle Management Act, which bans unauthorized changes to a car that can affect safe operation. The maximum penalty is two years in prison or a fine of up to 20 million won, roughly $14,000. The transport ministry had already warned owners about this in late March, and in April it asked police to investigate after it found signs of unauthorized activations. Police told Korea JoongAng Daily that safety risks were confirmed, including the chance that FSD misreads the driving situation. Police say they will keep investigating, with technical advice from the ministry and the Korea Transportation Safety Authority.

Why can't most Korean Teslas use FSD legally?

Because they are built in Shanghai, not in the US. Tesla launched FSD (Supervised) in South Korea in late 2025, but only for US-built cars: the Model S, Model X and Cybertruck. Those vehicles are exempt from Korean safety certification under the free trade agreement between Korea and the US. The far more popular Model 3 and Model Y sold in Korea come from Giga Shanghai and have not been cleared under Korean safety rules for the feature, so FSD stays switched off, even though the software is in the car.

How many Korean Teslas can legally use FSD depends on whose numbers you use:

• Government data released in May by lawmaker Park Yong-gap put it at 4,292 of 180,684 registered Teslas, or 2.4%.
• Carisyou Data Lab, cited by Korea JoongAng Daily, counted 47,458 of 229,311 Teslas as of August, or 20.7%.

Either way, a large majority of owners are locked out. Some of them paid more than $6,000 for the FSD package anyway, in the hope it would be enabled later.

What is Tesla doing about the devices?

It switches features off remotely. Tesla treats the devices as a cybersecurity threat. In April it began detecting them remotely and disabling driver assistance features on affected cars, with a message in the car saying an unauthorized third-party device had been found. Owners were told they would be fully liable for any crash and could lose warranty coverage. In China, some owners reportedly lost FSD access for good.

Why does this case matter?

It shows how big the demand is, and it puts pressure on Tesla. The case shows how much demand there is for FSD in markets where regulators have not approved it, and how far some owners will go to get it. Critics such as Electrek argue that Tesla sold FSD to Korean owners whose cars had no clear legal path to using it, and ask whether those buyers will be offered refunds. Tesla has not commented publicly on that question.

For regulators elsewhere, Korea is a test of how to deal with software unlocks that can be bought online. A criminal case against dozens of drivers sends a much stronger signal than warnings alone.

What should you watch for next?

Three open questions: the court case, approval and refunds.

• Whether prosecutors charge the 80 suspects, and what penalties courts hand down.
• Whether Korea opens a route to approve FSD on Shanghai-built Model 3 and Model Y cars.
• Whether Tesla offers Korean buyers of FSD a refund or transfer while approval is missing.