US safety officials opened a preliminary investigation into Tesla's Autopilot after identifying 11 crashes involving the driver assistance system, officials said Monday.
The incidents dating back to 2018 included one fatal crash and seven that resulted in injuries, according to the National Highway Traffic Safety Administration.
Tesla founder Elon Musk has defended the Autopilot system and the electric automaker warns that it requires "active driver supervision" behind the wheel, but critics, including in Congress, say the system can be easily fooled and have called for NHTSA to take action.
Testers with the magazine Consumer Reports demonstrated in a video that Autopilot could be fooled into driving with nobody behind the wheel, an exercise also shown in widely-seen videos on Tik-Tok and other social media platforms.
"A preliminary evaluation starts the agency's fact-finding mission and allows additional information and data to be collected," a NHTSA spokesperson said.
In April, Democratic Senators Richard Blumenthal of Connecticut and Ed Markey of Massachusetts urged NHTSA to probe a fatal crash in Texas involving a Tesla after law enforcement said there was no driver behind the wheel.
The senators said Tesla has been criticized for "misrepresenting" it systems and "giving drivers a false sense of security," according to an April 22 letter.
Tesla has said it does not believe the April crash involved Autopilot, and the incident was not included in NHTSA's list of 11 crashes.
Those incidents involved cases "in which various Tesla models crashed where first responders were active, including some that crashed directly into the vehicles of first responders," the spokesperson said.
"NHTSA reminds the public that no commercially available motor vehicles today are capable of driving themselves," the spokesperson said.
"Certain advanced driving assistance features can promote safety by helping drivers avoid crashes and mitigate the severity of crashes that occur, but as with all technologies and equipment on motor vehicles, drivers must use them correctly and responsibly."
Tesla shares fell 3.4 percent to $693 in early trading.