Tesla electric vehicles can feel more computer than car with software updates, that sleek touchscreen, and a memory drive that can fill up in the blink of an eye. 

That last one is a big issue, since the car’s computing system relies on a flash memory device (an embedded Multi-Media Controller, or eMMC) to execute most functions in the car. It’s responsible for turning on the heat, displaying maps and directions, playing music, and even locking the doors. In the past few months, reports of full cards in the main control unit where the car’s electronics are housed (the MCU), have come in. When the eMMC fails, it reportedly shuts down the car’s electronics system.

This is happening in older Tesla vehicles about four years old and older for Model X and S vehicles, which first came out in 2012. The car can technically still drive, but Teslas are known for relying heavily on their screens for controlling the vehicle beyond infotainment features. It’s not a death sentence, but the flash drive needs to be replaced. If your car is still under warranty, Tesla will replace the entire MCU.  

The issue stems from excessive use, or logs, written onto the memory card. Over time, the device is worn down, even if data gets overwritten continuously. Tesla vehicles are pumping out too many logs, wearing out the electronics for the flash memory, which powers the infotainment and other car systems. It’s the same type of memory and data storage system used in phones.

For the newer Model 3 car, Tesla CEO Elon Musk claims the excessive logging in the MCU “should be much better at this point.” 

Jason Hughes@wk057 · Oct 10, 2019


In the past month I’ve done repairs/replacements on over a dozen @Tesla MCUv1 units for customers suffering from eMMC flash failure.@elonmusk, you really need to tell the engineers to fix the logging wear in /var. It’s literally killing a huge percentage of these units.

Elon Musk@elonmusk

Should be much better at this point1,16011:35 PM – Oct 12, 2019Twitter Ads info and privacy72 people are talking about this

We reached out to Tesla for more information on what affected owners should do and what exactly Musk’s comment about memory storage improvement means. Did Tesla change the way data is coded or did it implement a more physical change with more space to fit more logs?

Tesla’s vehicle warranty is four years, or 50,000 miles. The battery has a separate warranty policy that varies for the three different Tesla models. Outside of warranty, the MCU fix will set you back up to $3,000 if you can find an independent technician who will work on Teslas, Tom’s Hardware reported. One tech Inside EV spoke with said he can change how the vehicle codes inputs so the flash components are spared all that use. He can also replace just the eMMC instead of the entire unit for a cheaper fix. Maybe Tesla can borrow some ideas to prevent the problem in the first place.

Too bad turning the car off and on doesn’t work as a quick fix.



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