NHTSA Complaint #11459610 — 2021 TESLA MODEL Y

All of these incidents occurred with adaptive cruise control engaged, and sometimes with lane keeping engaged. The vehicle frequently brakes, or slows dramatically, when on the freeway and there is no obstacle in the vicinity. Over the last three days I made the drive from Burbank to Anaheim along I-5. Always in the same area, the car would suddenly slow. In two out of the three incidents, the "max speed," which was set to 80, dropped to 45. Simultaneously, the car thought it was in a 55 mph zone (it was a 65 mph zone). In one of the three instances, the max speed was not changed, but the car still slowed dramatically. On the same commute, the car navigation always has me get off on Artesia Blvd, and then get right back on the freeway. The adaptive cruise has a configurable follow distance that the car seems to generally ignore. It's a number from 2 to 6 or so, and it's not clear what it's supposed to be (seconds or car lengths). It's rarely either, although it should represent seconds. When traffic comes to a complete stop, the car waits until it is too close to brake. When traffic begins moving, the car waits too long to start moving, and then accelerates excessively to catch up. Finally, when using the regular adpative cruise and lane keeping, I would signal lane changes and initiate the change. The car disengages steering but maintains cruise. In many cases, while still indicating the lane change, the car's lane departure warning will sound and it will attempt to correct my steering, which I have to physically override. My Nissan Leaf had adaptive cruise control, lane centering, and lane departure avoidance, and it never gave me these issues. Oh also, the Tesla frequently and erroneously warns of forward collision. It's really terrible, and it's due in no small part to the removal of the forward radar sensor.