Adaptive cruise or lane keeping misbehaves

The Office of Defects Investigation (ODI) received a petition requesting that ODI reevaluate its decision to deny DP20-001 on the basis that intermittent high electrical current demands on the vehicles' 12VDC systems may have caused some or all of the incidents examined by ODI in DP20-001. The petitioner bases this information on a review of open-source research and the DP20-001 denial. The petition and related materials can be reviewed at NHTSA.gov under the following ODI number: 11528471.

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 salien