Tesla self-drive mode filmed 'endangering passengers'
Videos posted online appear to show Tesla's new self-drive mode causing some cars to drive dangerously.
One appears to show a car suddenly trying to swerve off the road after exiting the motorway in Portland, USA.
Another appears to show a Model S Tesla swerving towards an oncoming vehicle.
Autopilot takes over driving functions such as steering and changing lane.
But Tesla said: "The driver cannot abdicate responsibility for driving."
Autopilot was released as a software update, with a note stating it was suitable only for motorway driving.
The two videos showing cars swerving took place away from the motorway lanes.
Tesla said: "The latest autopilot release is a hands-on experience to give drivers more confidence behind the wheel, increase their safety on the road and make motorway driving more enjoyable."
At the time of its release, Tesla chief executive Elon Musk said autopilot was still in test mode.
"The software is very new. We're being especially cautious at this early stage, so we're advising drivers to keep their hands on the wheel just in case," he said.
Another Miami driver said his car was driving at 75mph (120km/h) in a 60mph zone, resulting in it being pulled over by the Florida Highway Patrol. He posted pictures of the speeding tickets he had been issued.
Tesla told the BBC it was the driver had set the speed limit to 75mph, because autopilot does not set the speed limit. It also said speeding drivers were warned that they were breaking the limit.