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NHTSA Investigates Failing MCUs

maxse

Member
Apr 7, 2019
43
22
Boston, MA
Too funny...about 5 months ago just a few weeks after my warranty expired the screen started to bubble...service tech says this is typical electronics and just cough up the $1k to replace. I asked what would happen if my MCU failed shortly after and they tried to tell me it’s extremely rare and they only have seen it a few times :mad:.

I figured I would just live with the bubble for 6 months or so in hopes the MCU2 upgrade path would be available. Well here I am and I don’t think I will be given an option to pay for MCU2 just a paid replacement of the 8+ year old MCU1.
 
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SO16

Active Member
Feb 25, 2016
2,873
8,932
MI
Too funny...about 5 months ago just a few weeks after my warranty expired the screen started to bubble...service tech says this is typical electronics and just cough up the $1k to replace. I asked what would happen if my MCU failed shortly after and they tried to tell me it’s extremely rare and they only have seen it a few times :mad:.

I figured I would just live with the bubble for 6 months or so in hopes the MCU2 upgrade path would be available. Well here I am and I don’t think I will be given an option to pay for MCU2 just a paid replacement of the 8+ year old MCU1.


Or pay a few hundred for just a screen replacement (by buying one online if you can get one) and if the MCU1 fails, pay a few hundred to have just the EMMC replaced.
 
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maxse

Member
Apr 7, 2019
43
22
Boston, MA
Or pay a few hundred for just a screen replacement (by buying one online if you can get one) and if the MCU1 fails, pay a few hundred to have just the EMMC replaced.

I didn’t want to tread into that territory with no manufacturer support and how heavily these cars rely on software updates but yes, for some this path would work.
 
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SO16

Active Member
Feb 25, 2016
2,873
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I didn’t want to tread into that territory with no manufacturer support and how heavily these cars rely on software updates but yes, for some this path would work.

Could always go this route to get you by and then upgrade to MCU2 once available for your car. That would get you another 4 year warranty on the MCU. And supposedly the eMMC on MCU2 will last about 150 years compared to 4-5.
 
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jpvdheijn

Member
Oct 30, 2018
524
401
Baarle-Nassau, NL
Could always go this route to get you by and then upgrade to MCU2 once available for your car. That would get you another 4 year warranty on the MCU. And supposedly the eMMC on MCU2 will last about 150 years compared to 4-5.
I do not know what your 150 years claim is based on but I can already tell you that this can be the case for SSD storage but not for flash chip storage.
 

SO16

Active Member
Feb 25, 2016
2,873
8,932
MI
I do not know what your 150 years claim is based on but I can already tell you that this can be the case for SSD storage but not for flash chip storage.


Per green based on the size and amount of read/writes. But even if it just lasts the life of the car, that would be good.

Twitter
 

Chaserr

Hyperactive Hyperdrive
Sep 5, 2017
2,658
5,582
Logan
The EMMC on MCU1 was originally able to last 10+ years longer than now. Tesla's problem is the current firmware is 300% bigger than it was in 2012 and logging was increased. Eventually there was just too much data and the chip failed much sooner than it was designed to handle.

MCU2 firmware is increasing in size faster than MCU1 and logs just as much. Eventually they are going to have to stop adding new things like they needed with MCU1 or they will run into the same shortened lifespan problem. It will last longer but has the same intrinsic weakness to this mode of failure.
 

maxse

Member
Apr 7, 2019
43
22
Boston, MA
The EMMC on MCU1 was originally able to last 10+ years longer than now. Tesla's problem is the current firmware is 300% bigger than it was in 2012 and logging was increased. Eventually there was just too much data and the chip failed much sooner than it was designed to handle.

MCU2 firmware is increasing in size faster than MCU1 and logs just as much. Eventually they are going to have to stop adding new things like they needed with MCU1 or they will run into the same shortened lifespan problem. It will last longer but has the same intrinsic weakness to this mode of failure.

They don’t really care as these failures are typically outside the warranty period. So for them, continuing to release new features satisfies their customer base at the expense of the consumer...
 

MP3Mike

Well-Known Member
Feb 1, 2016
15,381
33,379
Oregon
I think the "safety issue" portion of this is a red herring, and not relevant. From everything I have seen the MCU fails before you get in and start driving, not while you are actually driving. So if you decide to drive you are making a conscious decision that you think it is safe enough to drive without those features being available. Also the back-up camera angle likely isn't going to fly since backup cameras weren't required when MCU1 cars were manufactured.

So that leaves other issues like HVAC controls. I have seen many cars, ex. Ford, where the HVAC modules are prone to fail out of warranty and prevent proper HVAC operation. Yet there have been no recalls for them that I have seen.

This is more similar to transmission and radiator issues that other OEMS, ex. Nissan and Mercedes, have had. If I recall correctly Nissan offered an extended warranty of a few years for the particular issue while Mercedes just said too bad, that'll be $4,000+ to fix. Someone filed a class action suit against Mercedes but it was thrown out. ("In dismissing the case, the judge ruled the plaintiff can't prove Mercedes committed fraud simply by showing some vehicles had radiators that eventually had problems.")

I think the difference here is that it appears that there will be a 100% failure rate of the MCU; most often right before, or after, the warranty period ends. (Maybe different for CPO/used cars that came with extended warranties.)

If Tesla has learned from this they will have made changes to make the MCU last longer. For example by reducing logging, which we have confirmation they have done. They could also put a bigger, or higher quality part in, which I have seen rumor of them doing in recent remanufactured MCUs.

I think the most likely outcome is that Tesla offers an extra 4-year warranty on the MCU, a total of 8-years from manufacture. (And hopefully putting better parts in going forward.) I don't expect an actual recall, since this isn't likely an issue that puts you in danger while you are driving. (Not that there should be a recall for everything that can fail putting you in danger while you are driving.)
 

ICE collector

Have a nice day!
Feb 28, 2019
91
9
San Diego, CA
I read most of these, & I find it strange that Tesla would not just replace the screen, so they can learn how to make better screens regardless if it rare or not, its the main control interface for the vehicle, & it gets so far less usage time than a phone or tablet, so as much as I get that it cost Tesla money to fix these displays, its just another engineering problem they have to fix, preferably not at the customer cost.
 

viper2ko

Active Member
Aug 30, 2017
1,421
1,359
USA
I read most of these, & I find it strange that Tesla would not just replace the screen, so they can learn how to make better screens regardless if it rare or not, its the main control interface for the vehicle, & it gets so far less usage time than a phone or tablet, so as much as I get that it cost Tesla money to fix these displays, its just another engineering problem they have to fix, preferably not at the customer cost.

Isn't anything to investigate. Small emmc, cheap emmc, over logging, and robust software updates shortened the mcu1 life. They fixed the overlogging but the damage was done. Some people have argued mcu1 orginally would have lasted longer. But V10 accelerated death. I'm sure Tesla will ignore and fight this until the very end. In their eyes they fixed it with MCU2. They never seem to do right by the older owners. We were the guinea pigs.
 

SO16

Active Member
Feb 25, 2016
2,873
8,932
MI
Isn't anything to investigate. Small emmc, cheap emmc, over logging, and robust software updates shortened the mcu1 life. They fixed the overlogging but the damage was done. Some people have argued mcu1 orginally would have lasted longer. But V10 accelerated death. I'm sure Tesla will ignore and fight this until the very end. In their eyes they fixed it with MCU2. They never seem to do right by the older owners. We were the guinea pigs.

Im just glad I can get the MCU2 upgrade. I didn’t expect that to happen.

Would be nice if the EMMC could be fixed for free and it may come to that. But fortunately we have options even if not ideal.
 

maxse

Member
Apr 7, 2019
43
22
Boston, MA
I would stress to anyone experiencing the early signs of MCU failure and is handy to remove and send out their tegra for preventative replacement by a third party. It’s definitely an inconvenience for several days but beats waiting a month or longer without your vehicle.

They were able to get me into a rental although it has chill mode enabled by the SC. Can’t really blame them lol

Tesla service just took in my Model S and they think it could be a month or longer before they receive the parts and they have several vehicles waiting ahead of mine with dead MCUs.
 

David.85D

Active Member
Oct 29, 2016
1,400
1,147
USA
Tesla service just took in my Model S and they think it could be a month or longer before they receive the parts and they have several vehicles waiting ahead of mine with dead MCUs.

Getting caught without replacement parts available is just further insult to the affected owners. We were days away from buying another Tesla then battery gate then my own MCU failure. Then drive unit. Then main battery. Don’t think the wife would take one for free at this point. They’ve done real harm to the Tesla brand with the changes to service.
 

rooter

Member
May 13, 2018
710
863
Edmonds, WA
Heat can't help, but many have claimed the car is never in extreme weather, garaged, etc, yet they have had an early failure.
It's not about ambient heat. Electronics have a common failure mode where when they warm up to some degree, they fail. I've had success spraying cold on eMMC and recovering the data. So in electronics terms, it's a "heat-related failure". It's a cheap chip.

And pulling dumps from all partitions gives inconsistent dumps. (sha256sum) This indicts the controller circuitry of the chip, rather than a given partition 'wearing out'.
 

MP3Mike

Well-Known Member
Feb 1, 2016
15,381
33,379
Oregon
If we can get enough people to file a complaint....Tesla will finally do something about it

I don't think it matters how many people submit a complaint at this point. The NHTSA has already requested information from Tesla on every vehicle with a MCU1 installed and what the condition of the eMMC is, how many have been fixed under warranty, how many have been fixed by Telsa out of warranty, and how many appear to have had the eMMC replaced with a third-party chip. (Along with requesting a lot of additional information.)

While responding to that request Tesla might decide it is best to issue a voluntary recall. Or not. I guess we will see.

Just as a data point: what is pretty much the equivalent of NHTSA in the UK has already reviewed the MCU failings and determined that it isn't a safety issue that requires a recall because it doesn't impact the ability of the driver to safely control the vehicle, pull over, and determine if it is safe for them to continue to drive. (Or something along those lines.)
 

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