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A Single Component Can Brick Older Teslas

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101–106 of 106 posts

Re: A Single Component Can Brick Older Teslas

#101

Earlier quoted context omitted.

The under lying issue can not be fixed with software. the eMMC is simply running out of write cycles. BUT they can mitigate the issue by not writing the syslog to the eMMC allowing the remaining write cycles to last much longer (This change could be done with a software update). On the newer versions of the Media Unit instead of disabling writing the syslog to the eMMC they added more storage to the processor boards…

The problem is that there is significant write amplification as the used space on the partition approaches the total space of the partition. To say that the choice to use eMMC is the fault is to say that ANY use of flash storage is a faulty decision. If there is sufficient space on the drive to mitigate write amplification, then the media will last a very long time indeed. Longer than the drivetrain, certainly. The p…

Most eMMC cards use really primitive wear levelling algorithms.

A simple firmware update to the eMMC chip could make it use a wear levelling algorithm that really does spread writes evenly over the whole chip. Current implementations simply use a sector till it goes bad and then using a spare till that goes bad, etc. After 1% or so go bad, the whole device rejects writes entirely.

With a decent implementation (like ssd's mostly do), you will never be able to kill a card in a lifetime.

Re: A Single Component Can Brick Older Teslas

#102

Earlier quoted context omitted.

eMMC is literally the equivalent of an SD card soldered down to the PCB. It’s more mechanically stable and also way faster. In my experience, removable SD wouldn’t hold up to an application like this.

An SD card might work fine if it is mounted properly. The slot found on a Raspberry Pi would not at all be sufficient. If it were held in and held against some robust contact pins it likely would be fine, even under automotive conditions. There are SIM card slots that are used on heavy vehicle computers and controllers (the ones that run the engine and so on) that are robust enough to hold a SIM card in place for yea…

Whenever I drop my phone I see the "SimProcessor" service spinning up...

I suspect that designing reliable spring contacts isn't as easy as it seems...

Re: A Single Component Can Brick Older Teslas

#103
post #80

Earlier quoted context omitted.

Isn't this more of a network effect than something inherent to Teslas?

Nope, tesla will not allow you to order parts, or even look at a service manual as a mere owner. Its crazy that people on HN of all places defend their customer-antagonistic practices.

[deleted]

Re: A Single Component Can Brick Older Teslas

#104

Earlier quoted context omitted.

An SD card might work fine if it is mounted properly. The slot found on a Raspberry Pi would not at all be sufficient. If it were held in and held against some robust contact pins it likely would be fine, even under automotive conditions. There are SIM card slots that are used on heavy vehicle computers and controllers (the ones that run the engine and so on) that are robust enough to hold a SIM card in place for yea…

Whenever I drop my phone I see the "SimProcessor" service spinning up... I suspect that designing reliable spring contacts isn't as easy as it seems...

Yeah, phones aren't designed to have robust SIM slots, they're designed to be thin, so they use very low profile SIM cradles that are not robust to impact.

The trade-offs for a high vibration environment are very different.

Re: A Single Component Can Brick Older Teslas

#105
post #91

Earlier quoted context omitted.

I think gatherhunter hit it dead on. It’s metrics thing and they wanted to close tickets. I sincerely doubt the FW update they pushed had anything to do with the issue being resolved. It is common practice (according to Tesla forums) to push FW before a service appointment just to be sure the car has the latest version before it goes in. The sketchy part for me is the inconsistency between the Service Tech and the re…

Presumably they know more about the root cause through looking at the logs. It would be so great if they could be more transparent about it. On the surface it doesn’t make sense that a FW issue would be causing an issue with your TM3. What about the other ~200,000 cars on the road? But to answer your last question, yes, it’s layers of incremental software functionality on the same hardware stack. Without knowing at w…

>left the cameras disconnected... AP worked but degraded

That’s very interesting, and closer to what I would expect.

The newest development, when I drove in this morning, the Service Tech said it’s a seatbelt sensor malfunction.

There is a “driver seat buckled” interlock for cruise control, but the alert for that explains the reason. I’m just getting “cruise not available” with no explanation.

Re: A Single Component Can Brick Older Teslas

#106
post #91

Earlier quoted context omitted.

Presumably they know more about the root cause through looking at the logs. It would be so great if they could be more transparent about it. On the surface it doesn’t make sense that a FW issue would be causing an issue with your TM3. What about the other ~200,000 cars on the road? But to answer your last question, yes, it’s layers of incremental software functionality on the same hardware stack. Without knowing at w…

>left the cameras disconnected... AP worked but degraded That’s very interesting, and closer to what I would expect. The newest development, when I drove in this morning, the Service Tech said it’s a seatbelt sensor malfunction. There is a “driver seat buckled” interlock for cruise control, but the alert for that explains the reason. I’m just getting “cruise not available” with no explanation.

Yeah I unbuckled once while AP was active to try to take off my coat and the car lost its shit on me. Red flashing alarms like, “WTF you doing?!”

I think that service tech was grasping at straws, unless he actually examined the logs and saw it written there. If it was the seat belt, wouldn’t you see it indicated on the display that the seat belt was unbuckled? It displays the unbuckled indicator for all seats that have occupants detected (weight sensor).

Presumably the logs will contain the exact reason it fails? Next time they text you maybe ask if they can tell you exactly what the log file says when AP engagement fails.

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