For a company that prides itself on its IT expertise, Tesla’s error in flash storage is hard to understand. But not impossible. That’s how they messed up.
The first Tesla cars have a serious problem: the big screens start to crash and turn black. Even worse, it prevents the cars concerned from reloading. Unless you replace a $ 1,800 circuit board, there is no easy solution.
Storage prevents the car from recharging?
According to the people of InsideEVs , the problem starts with the huge amount of system recording enabled on the car’s Media Control Unit (MCU), a single board computer running Linux. And an 8Gb eMMC flash memory chip is soldered to the MCU.
The eMMC is a small solid state drive (SSD) with an onboard controller. The eMMC has a standardized interface that allows card designers to easily add storage without worrying about all the details needed for proper operation of the flash module.
The main problem with the flash is that it wears out. Write on it enough times and it will stop accepting new data. The controller ensures that the bits are written with a technique known as wear leveling.
What happened ?
Someone at Tesla activated the connection to the MCU for no good reason. The constant writing of log logs on the eMMC, data that is rarely needed, means that the eMMC eventually wears out much faster than expected and that the firmware of the eMMC is no longer readable, so that the MCU no longer works.
And logging logs is not the only problem. The firmware stored on the eMMC has grown from around 30 MB to 1 GB over the years. The recording therefore has less available capacity, and the firmware updates require a writable eMMC.
Due to wear leveling and other techniques, flash wear is no longer a problem today unless you do something stupid. As’
Third parties (companies other than Tesla) can replace the chip on the MCU. But it’s a tedious process. But less expensive than replacing the entire card. What does Tesla do. Third parties write syslog data to a RAM disk, which does not wear out, but is volatile.
I suspect that the real problem here is that the guys in the software did not think about the impact of the connection on the embedded storage, since this is the hardware.
Since this is clearly a manufacturing issue over which customers have no control, Tesla should take care of all warranty repairs. It’s the right thing to do.