At one point in time, it turned out that Tesla's software folks were logging data to the hard-wired (as in, soldered to the circuit board) flash drive in the computer. All well and good, but it turned out that the
amount of spare storage was limited. The result of this was that a certain number of blocks of flash were being written over and over and over again.
A block in a flash drive does
not last forever; they have a limited life time. The flash drive manufacturers know this and play a game called, "wear leveling" where, when a particular block has a higher usage than other blocks, then the firmware in the flash drive swaps a less-used block for a more-used block and continues on. This is not actually noticed by the higher level operating systems; it's kind of a double-indirection game. In addition, the better grades of flash keep spare sectors around for this purpose and swap them into the mix as they go.
But all good things come to an end, and beating on one particular spot on a nearly full flash device is a recipe for failure. This happened to a number of Tesla computers, oh, about three years ago. Two things happened, once it became clear what was going on:
- Tesla's software guys pushed out a load that Stopped Doing That Extreme (well, in retrospect, extreme) logging, thus saving a largish number of computers from immanent death.
- A few enterprising techies figured out what device it was. People would dismount their (failing) computers and send them to one of these guys. The techie would remove the part, carefully (it can be done: I'm an engineer on these kinds of things, trust me), extract the data from it, program an identical but new device with that same data, mount the new device in the computer, verify operation, and send it back. Ta-da! Working computer, cheaper than a new one.
So, an oldish computer from the time frame in question with lots of miles? Next question.. Of course, hardware can fail for any number of reasons, flash memory included. But this particular fault comes to mind.
But you've got a HW3 computer! Now you can run FSD if you've got $15k wearing a hole in your pocket..