Federal auto safety regulators have granted Tesla a five-week extension to respond to a government investigation into its Full Self-Driving software, which has been linked to dozens of reported incidents involving vehicles running red lights, traveling the wrong way on roads and colliding with other vehicles. The National Highway Traffic Safety Administration set a new response deadline of Feb. 23, extending the original Jan. 19 date, according to the agency.
The NHTSA inquiry, opened in October 2025 and covering 2.9 million Tesla vehicles equipped with FSD technology, represents one of the most significant federal reviews of a driver-assistance system to date — arriving as Tesla’s core vehicle-sales business is contracting and the company has placed heavy bets on autonomous driving to restore its growth.
Investigation scope and complaint record
The NHTSA investigation covers essentially every Tesla vehicle equipped with the Full Self-Driving feature. In a letter to the company dated Dec. 3, 2025, the agency said it was investigating 62 complaints, up from 58 reported incidents when the probe was first opened in October.
Regulators said many Tesla drivers involved in accidents reported that the cars gave them no warning before behaving erratically, the Associated Press reported.
Tesla, headed by CEO Elon Musk, has argued to regulators and in court that the company has repeatedly told drivers the FSD system cannot operate the vehicle without human oversight and that whoever is behind the wheel must be ready to intervene at all times.
What FSD is — and what critics say it is not
FSD is classified as Level 2 driver-assistance software, meaning it requires drivers to maintain full attention to the road at all times. Critics have argued that the “Full Self-Driving” name is a misnomer that has led drivers to cede more control to the system than federal safety standards permit.
Tesla introduced a new version of FSD in the fall of 2025. The company is also testing a more advanced iteration that would not require driver intervention — an autonomous capability that Musk has been promising to deliver for years.
Sales decline and the stakes for Tesla
Tesla delivered 1.64 million vehicles in 2025, down 9% from the prior year, the company reported earlier in January. The company lost its position as the world’s bestselling electric vehicle maker to Chinese rival BYD, which sold 2.26 million vehicles in 2025.
The sales decline has been attributed to a combination of factors, including the expiration of U.S. federal tax credits for buyers, increased competition and, according to reporting by the Associated Press, backlash to Musk’s political activities.
Tesla’s push to commercialize FSD and its ambitions in robotaxi services have become increasingly central to how investors are valuing the company. Tesla stock finished 2025 with a gain of approximately 11% and was trading at about $439 per share in midday trading Friday, essentially unchanged on the day.