Seatbelt tone or malfunction Tesla announces the largest recall in history

Tesla is recalling more than 817,000 cars of all types across the U.S. because the seatbelt tone may not ring when the cars are up and the driver is not fastening their seat belts.

According to documents released Thursday by safety regulators, the recall relates to model S and Model X SUVs for models 2021 and 2022, as well as Model 3 and Model YUV models 2020 to 2022 for models 2017 to 2022.

The Federal Motor Vehicle Safety Act requires a sound to sound when a car starts and stops when the front seat belt is fastened.

Tesla will address this issue earlier this month with an over-the-air software update. The National Highway Traffic Safety Administration (NHTSA) said drivers may not know they were not wearing seat belts without a tone, which increases the risk of injury in a crash.

Tesla said in the filing that no accidents or casualties have been found due to the problem. Visual seatbelt reminders in the car are still displayed.

On January 6, the Korea Automotive Testing And Research Institute discovered the problem. Tesla conducted an investigation on Jan. 25 and determined that a recall was needed, the filing said.

If the vehicle exceeds 13.7 mph and the driver's seat belt is not fastened, the warning will still sound, the report said.

The recall is one of the largest in Tesla's history and covers all four models in the company's product line. According to Motorintelligence.com estimates, Tesla has sold just over 1 million vehicles in the United States since 2013.

Tesla is facing increasing scrutiny from NHTSA. Earlier this week, the agency announced that Tesla would recall nearly 54,000 cars and SUVs because of their "fully autonomous driving" software that would allow them to pass through stop signs without a full stop.

Recall documents released Tuesday say Tesla will disable the "rolling stop" feature through a software update. The feature allows vehicles to pass through intersections with full stop signs at 5.6 miles per hour.

NHTSA is also investigating multiple complaints, including one that Tesla's "fully autonomous driving" software caused a crash in California. Other complaints allege that the slightly less intelligent "autonomous driving" driver assistance system has repeatedly hit emergency vehicles parked on the road.