Preventive eMMC replacement on MCU1

[GlmnAlyAirCar]

Is there some type of seal on the MCU that you need to break to get into the guts? Like a warranty seal?

Just have to pull the screen out of the housing carefully. It fits pretty snug. Just make sure you remove all 12 screws. I missed one the first time and bent a bracket. Fortunately, it was easy to reshape.

I just finished putting my MCU back in after having the emmc replaced by @TonyT . All works great!

 

[Gu$ G]

Just have to pull the screen out of the housing carefully. It fits pretty snug. Just make sure you remove all 12 screws. I missed one the first time and bent a bracket. Fortunately, it was easy to reshape.

I just finished putting my MCU back in after having the emmc replaced by @TonyT . All works great!

Do anyone that has successfully done this replacement, have you noticed improvement in your MCU performance?

I'm looking at doing this preventatively. I realize its important to avoid a catastrophic failure, so I'll do it either way. But I'm wondering if map drawing, internet, or bluetooth will be improved? I'm driving a Signature P85 so I feel like it may just be too old!

 

[David99]

Do anyone that has successfully done this replacement, have you noticed improvement in your MCU performance?

I'm looking at doing this preventatively. I realize its important to avoid a catastrophic failure, so I'll do it either way. But I'm wondering if map drawing, internet, or bluetooth will be improved? I'm driving a Signature P85 so I feel like it may just be too old!

I had lags and random freezing up on my center screen. That's gone. I have also upgraded to 4G (from 3G) so some of the speed improvements I definitely see are probably more due to the faster connection. Bluetooth was unreliable and had issues. That's gone. I would highly recommend to replace the chip to anyone with an older car.

 

[TonyT]

One of my really bad cases had a car that needed a reboot daily in order to function. After the upgrade the car has not needed a single reboot.

 

[GlmnAlyAirCar]

Do anyone that has successfully done this replacement, have you noticed improvement in your MCU performance?

I'm looking at doing this preventatively. I realize its important to avoid a catastrophic failure, so I'll do it either way. But I'm wondering if map drawing, internet, or bluetooth will be improved? I'm driving a Signature P85 so I feel like it may just be too old!

I can’t say I’ve noticed anything decisively faster, but it does seem that my 3g connects faster and nav routes quicker. Of course this could just be my perception.

 

[Dukeybootie]

Map loading seems a bit faster. It had slowed down a ton prior to eMMC replacement. My peace of mind has improved greatly though =)

 

[TonyT]

Map loading seems a bit faster. It had slowed down a ton prior to eMMC replacement. My peace of mind has improved greatly though =)

Actually one of my friends had maps loading so slow it literally took over a minute when he resized the screen. He actually sent me a video so no exaggeration. It became a painpoint for him showing Tesla Tech to his friends and was actually embarrassing. I can totally understand. Once replace it was like a brand new car, so snappy! Maybe I can get him to chime in.

 

[widodh]

I can confirm that it seems like the eMMC replacement helped a lot. The MCU caches Spotify and Google Maps tiles locally. Once the eMMC gets older it writes slower.

My new Swissbit 64GB eMMC is also a lot faster than the original 8GB, so that makes a difference as well.

I have the feeling the MCU crashes less and just works smoother.

 

[TonyT]

I can confirm that it seems like the eMMC replacement helped a lot. The MCU caches Spotify and Google Maps tiles locally. Once the eMMC gets older it writes slower.

My new Swissbit 64GB eMMC is also a lot faster than the original 8GB, so that makes a difference as well.

I have the feeling the MCU crashes less and just works smoother.

My current original eMMC chip is wiring at about .7 meg /sec I've tested new 32 gig swissbits at about 20 meg/sec. Will have to see if I can find my 64 test, I think it was a good amount above 20 in my non scientific tests.

 

[MP3Mike]

I've tested new 32 gig swissbits at about 20 meg/sec.

Is that test of the swissbits eMMC in the Tesla MCU or in some other device?

 

[widodh]

My current original eMMC chip is wiring at about .7 meg /sec I've tested new 32 gig swissbits at about 20 meg/sec. Will have to see if I can find my 64 test, I think it was a good amount above 20 in my non scientific tests.

I'd have to test again, but I think my 64GB wrote with about ~30MB/sec at 4k writes. Much faster than the previous eMMC.

Since Google Maps and Spotify cache locally on the eMMC it's not that weird that a new eMMC makes the MCU respond faster.

 

[TonyT]

Just have to pull the screen out of the housing carefully. It fits pretty snug. Just make sure you remove all 12 screws. I missed one the first time and bent a bracket. Fortunately, it was easy to reshape.

I just finished putting my MCU back in after having the emmc replaced by @TonyT . All works great!

New doc will be ready soon on a web url, with pics and videos Do be super careful opening and removing. There are ribbon cables all around the mcu screen when removing the mcu from car to be careful with, and the ribbon cables inside when opening. Breaking them can lead to loss of touchscreen or display.

 

[random155]

New doc will be ready soon on a web url, with pics and videos Do be super careful opening and removing. There are ribbon cables all around the mcu screen when removing the mcu from car to be careful with, and the ribbon cables inside when opening. Breaking them can lead to loss of touchscreen or display.

That would be great to have a tutorial on MCU removal.

 

[Gu$ G]

I just pulled my eMMC and sent it over to TonyT. I'll post my experience and lessons learned in the next few days.

My car is running without the Tegra board but it won't charge. Anyone have suggestions on how to get it to charge at the low rate?

The car says "Charging Complete" even though the battery is at about 194 miles (210 would be about 80% and 230 or so would be full). The IC says 0/56A.

FWIW the car is a Signature 2012 P85.

 

[scottf200]

.... Anyone have suggestions on how to get it to charge at the low rate?
The car says "Charging Complete" even though the battery is at about 194 miles (210 would be about 80% and 230 or so would be full). The IC says 0/56A.
FWIW the car is a Signature 2012 P85.

Author: Engineering Explained -- 2.49M subscribers

 

[TonyT]

Consolidated eMMC Thread (MCU repair)

 

[dogphlap]

I'm starting to see errors that look like a failing eMMC IC. To remove the MCU can I start by removing the 12V lead acid battery (I have the frunk out at the moment and that battery is particularly easy to get at on my 2015 70D Model S). Won't that release the main contactors in the traction battery pack meaning all sources of power will be removed ? Will the car just power up as per normal when the 12V battery is reconnected or is it not that simple ?

 

[TonyT]

yes, I've only removed the fuse for the MCU, full power removal from 12 is also fine, but make sure your windows are open, don't lock yourself out. I think there is something that says to remove the HV loop also, which is a good idea. Once you remove the Tegra, put the mcu back together and in the car, then put the fuse back. You will have a 30 second delay before you can drive once you press the brake with key in the car.

I'm starting to see errors that look like a failing eMMC IC. To remove the MCU can I start by removing the 12V lead acid battery (I have the frunk out at the moment and that battery is particularly easy to get at on my 2015 70D Model S). Won't that release the main contactors in the traction battery pack meaning all sources of power will be removed ? Will the car just power up as per normal when the 12V battery is reconnected or is it not that simple ?

 

[dogphlap]

yes, I've only removed the fuse for the MCU, full power removal from 12 is also fine, but make sure your windows are open, don't lock yourself out. I think there is something that says to remove the HV loop also, which is a good idea. Once you remove the Tegra, put the mcu back together and in the car, then put the fuse back. You will have a 30 second delay before you can drive once you press the brake with key in the car.

Thanks very much TonyT. It was mostly the powering up that I was nervous about, glad I don't need some special Tesla Service department password. The 12V battery is at least 4.5 years old so I figured I'd change that. Just prior to Christmas I bought a LiFPO one that may do the job but since then the car has started displaying classic eMMC fail symptoms and just an hour ago I got a '12V battery requires service' 'Replace 12V battery soon' notification on the driver's binnacle display. Starting to look like my traditional technique of masterful inactivity will have to give way to actually doing something. For what it may be worth the old 12V battery is currently sitting at 13.73V, daring me to replace it.

 

[.jg.]

I have read elsewhere a post that suggested updates since 2019.40.x.x may have closed off backdoors/access in the MCU. Does anyone know if there is there any truth to this and if would it have any impact for eMMC replacement?