Unexpected Brake Activation

What NHTSA is examining

On February 16, 2022, the Office of Defects Investigation (ODI) opened a Preliminary Evaluation (PE22002) to investigate reports of unexpected deceleration while driving with the adaptive cruise control system engaged in Model Year (MY) 2021 – 2022 Model 3 and Model Y vehicles manufactured by Tesla. The subject systems include Autopilot (all versions), Full Self-Driving (FSD) and Traffic Aware Cruise Control (TACC). These complaints have been colloquially referred to as “phantom braking”. ODI opened PE22002 to determine the scope and severity of the potential problem and to assess any resulting safety issues in the subject vehicles. The alleged defect is an unexpected and unrequested vehicle deceleration triggered by the subject system during subject system engagement. The alleged defect does not occur when the subject system is not in use and is separate and distinct from Automated Emergency Braking (AEB). During vehicle operation, AEB is actively monitoring in the subject vehicles regardless of subject system and its intervention is accompanied by audible and visual collision warnings. A Vehicle Owners Questionnaire (VOQ) trend originating in November 2021 prompted ODI to open PE22002. VOQ narratives reported unexpected brake activation while using TACC, Autopilot or FSD. The trend grew from 99 by the end of 2021 to 314 by February 16, 2022, when PE22002 was opened. ODI sent Information Request (IR) Letters to Tesla on May 4, 2022, and July 11, 2024, to request salient…

Vehicles under investigation