The US agency responsible for regulating road safety revealed on Friday that it is investigating Tesla, owned by billionaire Elon Musk, over its self-driving software systems.
The National Highway Traffic Safety Administration's assessment covers about 2.4 million Tesla vehicles manufactured between 2016 and 2024.
The NHTSA's action is the first step before a potential recall that the agency is seeking to implement against the company.
Tesla did not respond to the BBC's inquiry about the investigation.
The NHTSA's initial assessment comes after four reports of crashes involving Tesla's "Full Self-Driving" or "FSD" software.
The agency said the crashes involved poor visibility on the road, fog or glare from the sun.
The NHTSA said one of the crashes involved a Tesla hitting pedestrians, killing them, and another involved one person being injured.
The evaluation is intended to determine whether Tesla’s self-driving systems are capable of handling and responding appropriately to poor road visibility, and will also assess whether other self-driving accidents have occurred under similar conditions.
The agency noted that despite the name, full self-driving is actually a “partial self-driving system.”
The NHTSA announcement comes a week after Musk unveiled the Cybercab at Warner Bros. Studios in California.
At the event, Musk said the concept of a fully autonomous robotaxi, which operates without pedals or a steering wheel, would be on the market by 2027.
But some analysts and investors weren’t impressed.
The company’s stock has fallen 8 percent since the Cybercab launch, having been mostly flat before the NHTSA announced the investigation.
In contrast to Waymo, the self-driving car company run by Alphabet, the parent company of Google, Tesla’s self-driving systems rely heavily on cameras and artificial intelligence.
Musk's approach is less expensive than using high-tech sensors like LiDAR and radars, which are crucial to Waymo's self-driving car program.
