The agency explains in a document that it has received 354 complaints over the past nine months related to this problem on 2021-2022 Model 3s and Model Ys driving with Autopilot cruise control, a function that adapts the speed of the car to that of surrounding traffic in all four lanes.
They describe a "phantom braking" situation, with a vehicle suddenly braking for no apparent reason.
These rapid decelerations can occur "without warning, randomly and often several times during the same trip", details the NHTSA.
The agency has therefore decided to open an investigation to determine the extent and severity of this potential problem.
416,000 vehicles could be affected.
The agency already opened an Autopilot investigation last summer after a series of Tesla collisions with first-response vehicles.
As part of this investigation, she repeatedly requested additional information from Tesla on its driver assistance systems.
Tesla, which has dismantled its service answering questions from journalists, did not immediately respond to a request from AFP.
Elon Musk's group is under increased scrutiny from the NHTSA.
At the beginning of February, the group initiated four recalls in two weeks, in particular to deactivate functions making it possible not to come to a complete stop at the stop sign or to emit a sound outside the car that could mask the sound intended to alert pedestrians. the presence of the vehicle.
The NHTSA had also pushed the group at the end of December to update its software to prevent drivers from playing video games on the car's system when it is in motion.
© 2022 AFP