In a letter, the National Highway Traffic Safety Administration reminded Tesla that federal law requires automakers to initiate recalls if they find defects that pose a safety risk.
The federal government’s top auto-safety regulator is looking into why Tesla did not issue a recall last month when it updated software in its cars to improve their ability to spot stopped emergency vehicles such as police cars and fire trucks. The regulator, the National Highway Traffic Safety Administration, has also ordered Tesla to provide data about its Full Self-Driving software, which it has allowed a small set of owners to test on public roads. NHTSA opened a formal investigation over the summer into 12 crashes in which Tesla cars operating in Autopilot mode — a driver-assistance system that can steer, brake and accelerate a car on its own — failed to detect stopped emergency vehicles that had their lights flashing in low light.
