NHTSA Preliminary Evaluation PE20010

On June 22, 2020, the Office of Defects Investigations (ODI) opened Preliminary Evaluation PE20-010 to investigate incidents of media control unit (MCU) failures resulting in loss of rearview camera in model year (MY) 2012-2015 Tesla Model S vehicles equipped with the NVIDIA Tegra 3 processor with an integrated 8GB eMMC NAND flash memory device. EMMC NAND flash devices have a finite lifespan based upon the number of program/erase (P/E) cycles. The subject MCU allegedly fails prematurely due to memory wear-out of the eMMC NAND flash. Tesla used the same MCU with the Tegra 3 processor in approximately 159 thousand 2012-2018 Model S and 2016-2018 Model X vehicles built by Tesla through early-2018. In response to ODI's Information Request (IR) for PE20-010, Tesla provided ODI with 2,399 complaints and field reports, 7,777 warranty claims, and 4,746 non-warranty claims related to MCU replacements. The data show failure rates over 30 percent in certain build months and accelerating failure trends after 3 to 4 years-in-service.According to Tesla, for subject vehicles equipped with the NVIDIA Tegra 3 processor with an integrated 8GB eMMC NAND flash memory device, the eMMC NAND cell hardware can fail when reaching lifetime wear, for which the eMMC controller has no available blocks to recover. With this failure mode, the only recovery available is a replacement of the eMMC device, achieved by physical part replacement of either the MCU assembly or visual control module subcomponent. Tesla provided the effects of MCU failure on vehicle function which result in loss of rearview/backup camera, loss of HVAC (defogging) setting controls (if the HVAC status was OFF status prior to failure.) There is also an impact on the advanced driver assistance support (ADAS) Autopilot system, and turn signal functionality due to the possible loss of audible chimes, driver sensing, and alerts associated with these vehicle functions. There are precedents for addressing defects that result in los