Surviving family members of a 44-year-old Japanese man who was struck and killed by one of its electric cars in April 2018 filed the lawsuit in San Jose federal court on Tuesday.
Yoshihiro Umeda, who was 44 when killed in the auto crash, is described in the complaint as the first "Tesla Autopilot-related death involving a pedestrian," and claims the tragedy illustrates a "patent defect" in Tesla's technology.
Tesla, led by Elon Musk, is based in Palo Alto, California, and sells cars with automated driver assistance systems. The court motion, submitted by the victim's spouse Tomomi Umeda and daughter Miyu Umeda, was first reported by Bloomberg.
Yoshihiro Umeda was killed on April 29, 2018, after being hit by a Tesla Model X that "suddenly accelerated" when a car in front of it switched lanes, the filing says.
It adds that the Tesla vehicle crashed into a van, motorcycles and pedestrians that had stopped at the side of an expressway near Tokyo following an accident.
The documents allege the Tesla car, which had its Traffic Aware Cruise Control (TACC) feature engaged, sped up after the car in front moved, "rapidly accelerating from about 15 km/h to approximately 38 km/h" before striking the motorcycles and Umeda.
The driver was "found to have been dozing shortly before the crash," the filings note, adding plaintiffs expect the firm to "lay all of the blame" on that person.