DETROIT (AFP) – The US government has opened a formal investigation into Tesla’s semi-automated driving system, saying it was having trouble detecting parked emergency vehicles, a regulator said Monday.

The investigation covers 765,000 vehicles, nearly everything Tesla has sold in the country since the advent of the 2014 model. Of the accidents identified by the National Highway Traffic Safety Administration (NHTSA) as part of the investigation, 17 people were found injured and one died.

NHTSA says it has identified 11 incidents since 2018 where Teslas on Autopilot or Traffic Aware Cruise Control struck vehicles where first responders had flashing lights, flares, a lit arrow or hazard warning cones.

The research covers the full line of current Tesla Models, Model Y, X, S and 3 from the years 2014 to 2021.

Some Tesla drivers frequently misuse autopilot and have been caught drunk driving or in the back seat while the car was traveling on a California highway.

The agency has dispatched investigation teams to 31 accidents involving partially automated driver assistance systems since June 2016. Such systems can keep a vehicle centered in its lane and at a safe distance from vehicles in front of it. Of those, 25 were related to Tesla’s autopilot in which 10 deaths were reported, according to data from the agency.

Tesla and other manufacturers advise drivers to be prepared to intervene at all times, even when autopilot is on.

A message was left early Monday asking for comment from Tesla, which has dissolved its media relations office.

“The investigation will evaluate the technologies and methods used to monitor, assist and enforce driver compliance with a dynamic driving task while on autopilot,” NHTSA said in its research papers.