The agency said security video from the driver's home showed the driver and passenger getting into the front seats before driving away from the home.
Tesla Inc has disclosed two new fatal crashes involving automated driver assist systems to US regulators bringing its total to 16 in a government mandated data collection system set up last year.
Tesla has sent a cease-and-desist letter over videos from an advocacy group showing their vehicles hitting child-size mannequins with their full self-driving software apparently engaged.