The federal government’s chief auto-safety regulator has launched a preliminary investigation into a sudden brake strike by a Tesla car equipped with an advanced driver-assistance system called the company’s autopilot.
The National Highway Traffic Safety Administration said in a document posted online this week that it has been working to respond to 354 customer complaints about “phantom braking” in the last nine months – Teslas brakes unexpectedly when there is no danger on the road.
The investigation focuses on the Tesla Model 3 compact sedan and the Model Y hatchback, which were built in 2021 and 2022 and sold in the United States. The agency said it covers about 416,000 cars. The purpose of the preliminary investigation is to determine the scope and severity of the problem.
The complaints allege that the vehicle “applied its brakes unexpectedly while driving at highway speeds,” the safety agency wrote in a summary of the investigation. “Prosecutors state that rapid recession can occur randomly and repeatedly without warning.”
Tesla did not respond to a request for comment.
The investigation is the latest security concern Tesla has faced. Separately this year, Tesla recalled 54,000 cars equipped with its fully self-driving software to deactivate a feature that allows vehicles to move slowly at intersections without stopping under certain conditions. Failure to stop at the stop sign could increase the risk of a crash, the security agency said in a letter to Tesla.
The agency also launched a formal investigation last year into the autopilot and how it identifies objects and other vehicles on the road. That inquiry was prompted by 11 incidents in which Teslas police cars, fire trucks and other emergency vehicles operating in autopilots with flashing lights failed to stop.
In the last few months, Tesla has recalled 12,000 cars to fix the braking problem and recalled 458,000 others for two separate mechanical defects. It also agreed to discontinue a feature that allows drivers or front passengers to play video games on the dashboard touch-screen while the car is in motion. The issue was reported in The New York Times, and the security agency pressured the company to resolve it.