— A Tesla Model S and Model X media control unit failure recall of 2012-2018 Tesla Model S and 2016-2018 Model X vehicles convinced federal safety regulators to close down an investigation.
The National Highway Traffic Safety Administration upgraded a defect investigation in November 2020 to look at complaints about Tesla media control units (MCUs), the center display screens in 2012-2018 Tesla Model S and 2016-2018 Tesla Model X vehicles.
The Tesla media control units were equipped with NVIDIA Tegra 3 processors with integrated 8GB eMMC NAND flash memory devices.
NHTSA learned the expected usage life rating for the 8GB eMMC NAND flash memory device is about 3,000 “P/E” or "Program-Erase cycles, after which the eMMC NAND flash memory device would become fully consumed and no longer be operational, leading to a failure of the media control unit (MCU)."
Investigators did the math and figured 3,000 P/E cycles would take only five to six years. However, the typical lifespan of a vehicle is much longer than five or six years.
NHTSA said "a 5- or 6-year life expectancy for a component integral to providing the driver with safety functions is insufficient." And Tesla confirmed all the media control units will eventually fail based on the finite storage capacity.
Tesla also provided information about what happens when an MCU fails, including the loss of the rearview/backup camera and loss of HVAC (defogging and defrosting) setting controls if the HVAC was OFF prior to failure.
"The failure also affects the Autopilot advanced driver assistance system (ADAS) and turn signal functionality due to the possible loss of audible chimes, driver sensing, and alerts associated with these vehicle functions." — NHTSA
NHTSA sent Tesla a recall request in January 2021 and Tesla responded by disputing the need for a recall. However, Tesla did announce a recall of 2012-2018 Tesla Model S and 2016-2018 Model X vehicles.
The investigation is closed based on Tesla's recall, but NHTSA is monitoring the effectiveness of the recall repairs and will take additional action if warranted.
