24/7 New York news stream: Watch NBC 4 free wherever you are Magno warned that viewers of Tesla's online communications, including posts on X, may expect a car with the company's Full Self-Driving Supervised, or FSD, system to have the capabilities of a robotaxi even though they require human supervision, meaning a driver ready to steer or brake at any time. Tesla has until Dec. 18 to respond to NHTSA's letter, which also included requests for extensive information about the company's cars and FSD-related technology. A failure to respond could result in a maximum of $135.8 million in penalties. The company can also ask for an extension. The NHTSA is investigating possible safety defects in Tesla's FSD option, a partially automated driving system. The latest probe followed a series of Tesla collisions that involved the use of FSD within 30 seconds of impact. In one instance, a Tesla driver using FSD fatally struck a pedestrian.