>Tesla, Inc. (Tesla) is recalling certain 2017-2021 Model S and Model X vehicles. The electronic power assist steering (EPAS) system may experience a loss of power steering assist when driving on rough roads or after hitting a pothole.
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>Firmware release 2022.36 changed calibration values for the electronic power assist steering (EPAS) system. In rare cases on certain 2017-2021 Model S and Model X vehicles, the updated calibration values may result in reduced or lost power steering assist due to forces from external road dynamics (i.e., pot holes or bumps) being inadvertently classified as unexpected steering assist torque. Reduced or lost power steering assist does not affect steering control, but could require greater steering effort from the driver, particularly at low speeds.

Chronology

- On October 11, 2022, Tesla began broadly rolling out firmware release 2022.36 to the vehicle fleet, which included updated calibration values for the electronic power assist steering (EPAS) system to better detect unexpected steering assist torque.

- Beginning on October 18, 2022, Tesla identified an increasing rate of alerts related to the updated EPAS calibration values on certain 2017-2021 Model S and Model X vehicles.

- On October 19, 2022, Tesla began deploying firmware release 2022.36.5 to the vehicle fleet, which reverted the calibration values for the EPAS to pre-2022.36 values, while Engineering assessed potential root causes and evaluated the condition.

- From October 19, 2022, through October 24, 2022, Tesla investigated the alert occurrences and completed a risk assessment of the condition based on severity and rate of occurrence.

- On October 25, 2022, based on the risk assessment, Tesla made a determination to voluntarily recall the affected vehicles.

- As of November 1, 2022, Tesla identified 314 vehicle alerts for this condition among U.S. vehicles (received between October 11, 2022, and November 1, 2022) that are related to or may be related to this condition. Tesla is not aware of any injuries or deaths related to this condition.

https://static.nhtsa.gov/odi/rcl/2022/RCLRPT-22V818-6624.PDF