Is one of Tesla’s infotainment systems defective by design? That’s a question the National Highway Traffic Safety Administration hopes to answer. It has started an engineering analysis after hundreds of customer complaints of bricked systems resulted in a preliminary investigation in June.
NHTSA thinks it knows what the problem is: an 8GB eMMC NAND flash memory chip with a finite number of write cycles, fitted to its Media Control Unit. The MCU regularly writes logs to this chip and, within three or four years, reaches the lifetime number of cycles. At this point the touchscreen dies, taking with it functions like the car’s backup camera, the ability to defog the windows, and also the audible alerts and chimes for the driver aids and turn signals.
After the regulator’s Office of Defects Investigation received 537 complaints, it asked Tesla if it knew of any more problems with the Nvidia Tegra 3-based system, which is fitted to approximately 158,000 Models S (2012-2018) and X (2016-2018). Tesla did, handing over 2,399 complaints and field reports, 7,777 warranty claims, and 4,746 non-warranty claims.
The finite—and short—lifespan of these infotainment systems is a relatively well-known problem within the Tesla community. A video on the popular YouTube channel Rich Rebuilds that delved into the problem in May 2019 has racked up more than 669,000 views:
The discussion of the infotainment system failures begins around 9 minutes in.
As that video notes, and as Tesla told NHTSA, the time to failure for an MCU depends on how much its car has been in operation. Daily drive time, daily charge time, and streaming music over the Internet are all factors, Tesla told the regulator.
This isn’t the first time that Tesla’s choice of consumer-grade electronics, as opposed to automotive-grade, has gotten it in trouble. A separate problem affects the 17-inch touchscreen, which can fail due to high temperature—the kind of temperature experienced inside a parked car during summer, as opposed to an air-conditioned office.
