5 ms·

Luckily the only dynamic part of most of these ECU's are their diagnostics and logging mechanisms, nowhere near "huge swaths of functionality". Every other bit

Luckily the only dynamic part of most of these ECU's are their diagnostics and logging mechanisms, nowhere near "huge swaths of functionality". Every other bit of flash is written once at the factory and is never touched again. Now that we are seeing widespread adoption of OTA, it'll increase the amount of writes to program flash maybe 100 times over the life of the vehicle, but still within reasonable bounds. The issue is if OEM's ignore this limitation and tie mission critical portions of their systems to the memory partitions their diagnostic and logging mechanisms use (e.g Tesla). In reality if we are deploying OTA capabilities to these vehicles, there is absolutely no reason to be hammering your flash with logs, just upload them to the borg cube and be done with it.

aidenn0 5y ago
Many cars use eMMC to back the infotainment system. Recent non-tesla rentals I've driven have definitely had functionality that could only be accessed through the touch-screen. e.g. a Chrysler my mom rented a couple weeks ago had just temperature and fan control on knobs; everything else for climate was touch-screen only. What happens when the eMMC gives up the ghost in this car? I don't know, but I suspect you won't be able to e.g. manually put the defogger on...
- waiseristy 5y ago
  Good point, you are totally right. I don't drive a car which uses the infotainment system for mission-critical functionality. I've actually run it without the infotainment system in the car at all. Tesla's would effectively be bricked without the head unit functioning. Ford and the rest of the reputable OEMs know a thing or two about flash degradation though. It was actually a huge sticking point in one of my infotainment projects with them. So I don't expect all the OEMs to make the same bone-headed mistakes Tesla has
  - aidenn0 5y ago
    If you are allowed to share, what is the typical OEM specified lifetime for the infotainment flash part? I guessed 10 years in my original comment, but that was a gut instinct and completely uninformed.
    - waiseristy 5y ago
      Your guess would be nearly as good as mine, I worked as a vendor and never actually had to abide by the requirements the integrators over at the OEMs had to stick to. Usually when talking with them they would throw around "lifetime of the vehicle" requirements. For typical OEMs I think they consider that 15-20 years. Tesla, probably 10 lol! Though, in reality, if you baby your flash to last 15-20 years. You've probably designed it in a way that it has a chance to live a whole lot longer.

aidenn0 5y ago

Many cars use eMMC to back the infotainment system. Recent non-tesla rentals I've driven have definitely had functionality that could only be accessed through the touch-screen. e.g. a Chrysler my mom rented a couple weeks ago had just temperature and fan control on knobs; everything else for climate was touch-screen only. What happens when the eMMC gives up the ghost in this car? I don't know, but I suspect you won't be able to e.g. manually put the defogger on...

waiseristy 5y ago
Good point, you are totally right. I don't drive a car which uses the infotainment system for mission-critical functionality. I've actually run it without the infotainment system in the car at all. Tesla's would effectively be bricked without the head unit functioning. Ford and the rest of the reputable OEMs know a thing or two about flash degradation though. It was actually a huge sticking point in one of my infotainment projects with them. So I don't expect all the OEMs to make the same bone-headed mistakes Tesla has
- aidenn0 5y ago
  If you are allowed to share, what is the typical OEM specified lifetime for the infotainment flash part? I guessed 10 years in my original comment, but that was a gut instinct and completely uninformed.
  - waiseristy 5y ago
    Your guess would be nearly as good as mine, I worked as a vendor and never actually had to abide by the requirements the integrators over at the OEMs had to stick to. Usually when talking with them they would throw around "lifetime of the vehicle" requirements. For typical OEMs I think they consider that 15-20 years. Tesla, probably 10 lol! Though, in reality, if you baby your flash to last 15-20 years. You've probably designed it in a way that it has a chance to live a whole lot longer.