Tesla has been granted a five-week extension to respond to a U.S. investigation into whether its “full self-driving” feature violates traffic laws, according to the National Highway Traffic Safety Administration.
In a letter to Tesla, the agency said the company now has until Feb. 23 to answer the government’s request for information. The original deadline was Jan. 19, 2025.
The investigation was opened in October after the NHTSA said it had collected dozens of reports of Tesla vehicles running red lights or driving on the wrong side of the road while operating in what the company calls “full self-driving” mode. The NHTSA said the reports included crashes into other vehicles and injuries.
The agency said the investigation covered 2.9 million vehicles, essentially all Teslas equipped with full self-driving technology, known as FSD. Federal auto-safety regulators said in a letter to Tesla on Dec. 3, 2025 that it was investigating 62 complaints, up from 58 reported incidents in October.
Tesla, led by CEO Elon Musk, has argued to regulators and in court cases that it has repeatedly told drivers the system cannot drive the cars by itself and that whoever is behind the wheel must be ready to intervene at all times. Regulators, however, said many Tesla drivers involved in accidents reported that the cars gave them no warning before behaving erratically.
The FSD system under investigation is Level 2 driver-assistance software, which requires drivers to pay full attention to the road. The report said a new version of FSD was introduced in the fall, and Tesla is also testing a vastly upgraded version that does not require driver intervention—an upgrade Musk has been promising to roll out for years.
The investigation is also under scrutiny because of how Tesla markets FSD, and critics have argued that the name is a misnomer that has lulled drivers into handing full control over to their cars. Tesla faces pressure to show progress with FSD as its core business—selling cars—has been struggling.
Tesla lost its crown as the world’s bestselling electric vehicle maker last year, according to the report, for reasons including backlash to Musk’s right-wing politics, expiring U.S. tax breaks for buyers, and stiff competition at home and abroad. Tesla reported earlier this month that it delivered 1.64 million vehicles in 2025, down 9% from a year earlier, while Chinese rival BYD sold 2.26 million vehicles and became the world’s biggest EV maker.
Still, investors are betting that Tesla and Musk can deliver on plans for robotaxi services and on humanoid robots that can perform basic tasks in homes and offices. Reflecting that optimism, Tesla’s stock finished 2025 with a gain of approximately 11%, and the report said Tesla shares were essentially unchanged in midday trading Friday at about $439 each.