Welcome to Tesla Motors Club
Discuss Tesla's Model S, Model 3, Model X, Model Y, Cybertruck, Roadster and More.
Register

MCU1 Bricked After EMMC replacement?

This site may earn commission on affiliate links.
I know this is beating a dead horse and this subject has been covered in numerous threads. As a long time lurker I haven't posted until now, but I'm kind of at a loss about this situation.

I had been having issues in my 2012 Model S with the touchscreen glitching or acting up (no 3g/connectivity, static lines, not reacting to touch, etc.) Took the car to Tesla service center and paid out of pocket for the daughter board replacement, which was advised at the time (still awaiting refund..)

After the daughter board was replaced, the screen became almost bricked up. It began entirely blanking out. It started happening 2 weeks after the replacement, and now is an almost daily occurrence. My belief is that this may have occurred after the daughterboard was replaced.

I took it to Tesla and they said it doesn't have to do with the recall and the motherboard showed signs of failure and the only way to fix it is to go with the $1500 mcu replacement.
I filed a report with the NHTSA, because i've been unable to use my turn signals giving me road anxiety, or have temperature controls which has been very difficult this cold winter.

Possibly moot point in posting this, but I don't want to spend $1500 on my already depreciating vehicle, for something that 1. is a defect and related to the recall/safety issue, 2. happened perhaps as an effect of the daughterboard replacement.

Has anyone had something similar happen after replacing the EMMC? Is there anyway to have Tesla cover this, or would doing so just prove they are the responsible party which is why they are refusing to?
 
When was the work done? Do you know for a fact the board was replaced with the new 64gb chip, not just an old 8gb one?

Why have you not made a warranty claim on the work done? That should get you to the front of the line

If your car is in good shape, maybe just go MCU2.

If you think your car is depreciating now, just wait until you get a replacement!
 
  • Like
Reactions: Jaymc5
If you can't use turn signals or heater, have you updated to 2020.48.12.1 or later per Tesla guidance? If so, then you have a safety problem, and Tesla needs to fix it.

Go MCU2 now, while they still have parts. It will increase the value of your car and reports are it is well worth it. Hope for a refund later.
 
If you can't use turn signals or heater, have you updated to 2020.48.12.1 or later per Tesla guidance? If so, then you have a safety problem, and Tesla needs to fix it.

And they would, but they want $1,500 to fix it...

Parts fail, even safety related ones, outside of warranty on all makes of cars all the time. More often than not they aren't covered by a recall. If your flasher goes out on your GM it is a safety issue, but it isn't something they have to repair for free after your warranty expires. (Unless it is covered by a recall.)
 
And they would, but they want $1,500 to fix it...

Parts fail, even safety related ones, outside of warranty on all makes of cars all the time. More often than not they aren't covered by a recall. If your flasher goes out on your GM it is a safety issue, but it isn't something they have to repair for free after your warranty expires. (Unless it is covered by a recall.)
No saying it would be easy. First thing is to prove the 64GB was installed. There is a one year on parts and labor.
 
The emmc was replaced while in warranty, but I paid out of pocket as the recall wasn't required yet. It had never turned off or gone blank before the emmc was replaced. Two weeks after, the screen began blanking consistently.

It's up to date on software and I have no turn signals, no way to climate control the vehicle, and no access to any controls from the front screen. It's become a safety hazard while driving and uncomfortable as well. For me, it constitues a safety issue.

Yes, the FPGA issue is now occuring and it came after the daughter board was replaced. Found this article on Inside EVs related to this: Tesla Starts Reimbursing For MCUs Due To Recall, But There Are Some Issues

"Some people plagued with MCU issues also said they are due to FPGA (field-programmable gate arrays) errors.
FPGA is a programmable silicon chip installed in the motherboard of MCU. It handles a video overlay for the backup camera in the MCU. We talked about it with Jason Hughes (the Tesla hacker), and he mentioned he has not seen any failures on this “outside of a water-flooded MCU. A failure would either result in no backup camera or no MCU video.” If the FPGA is also an issue, that would mean the VCM daughterboard's replacement is not enough to fix the glitches. Only a complete replacement of the multimedia computer would solve the problem."

The Tesla Service center I took it to asked me to pay the diagnosis fee, and told me that this issue is "completely unrelated to the recall" and that I was responsible because it's the motherboard/fpga. I'm no engineer, so it's all gibber gabber, but the more I read into it, the more I think these things are absolutely connected and Tesla is trying to pass the cost of replacement to the customer. I asked the service center to provide the diagnosis/reports from the vehicle to show the issue. They said the engineers worked remotely, and that this information was not something they could share with me.

I also found this: https://static.nhtsa.gov/odi/inv/2020/INRL-PE20010-80992P.pdf

The tegra processor is connected to the FPGA/motherboard, so the failures which began shortly after the daughterboard replacement feel like they are connected.

I'm a lowly peasant who doesn't understand much of this but I'm trying because it doesn't sit right or feel right to me. I'm still waiting for a $400 reimbursement for the daughterboard and being told i need to spend $1500 more now.

1616083589407.png
 
If they didn't install a 64GB eMMC then that would be covered under the recall. But if something else has failed in his MCU such that he needs a whole new one it doesn't really matter.

they did install a 64gb eMMC. The car has less than 45k miles.
Ive seen many others saying they had similar issues after replacing the emmc pop up too, and were advised to upgrade to the mcu2 just as i was.

Is there any way to know if the emmc replacement could lead to or cause fpga failure or further mcu degradation?
 
that's the problem. they wont show me anything which proves it. they tell the service center rep this is the issue, and when I ask for documentation or proof or something, they tell me that is not available for me.

So the tech has already told you they found it not to be the eMMC. What proof would satisfy you? Would you have to watch them remove the eMMC daughterboard from a working vehicle and install it in yours and see that yours still didn't work?
 
"Some people plagued with MCU issues also said they are due to FPGA (field-programmable gate arrays) errors.
FPGA is a programmable silicon chip installed in the motherboard of MCU. It handles a video overlay for the backup camera in the MCU. We talked about it with Jason Hughes (the Tesla hacker), and he mentioned he has not seen any failures on this “outside of a water-flooded MCU. A failure would either result in no backup camera or no MCU video.” If the FPGA is also an issue, that would mean the VCM daughterboard's replacement is not enough to fix the glitches. Only a complete replacement of the multimedia computer would solve the problem."

From what Jason said in that quote the FPGA failing would only impact the display, so turn signals should still work. (@wk057 can you confirm that is correct?) Did Tesla tell you that the FPGA is what failed, or are you just running with that since we suggested that is a possible failure method?

Given that information, and the fact that the recent firmware, which you say you have, is supposed to allow the turn signals to work even when the MCU has failed would lead me to think that maybe a different part of the MCU has failed. (The MCU contains multiple separate computers.) @wk057 can you share what the common failure methods are for the MCU1 that you have seen besides the eMMC?
 
The display is not functional and has gotten worse since having the EMMC recall performed (with a refurbished 64gb chip.) Prior to this, the screen never went blank. It started happening after the recall about once a week. Then twice a week. And so on and so forth. A month ago i took it to tesla to have it checked and mentioned it occurred after the recall was performed, they said it wasnt related and that the fpga was failing and i need to upgrade to mcu2 and pay $1500 for the fix.

It's gotten progressively worse, now to the point where the screen never turns on at all. I have no turn signals, nor functions of the screen, and cannot use my tesla app to control climate either. Essentially, I'm limited to just seeing the front screen.

i feel unsafe driving the vehicle.

i am late to all the forum threads about the mcu issue, but i'm trying to understand if there's a correlation between the emmc being replaced and the fpga failing shortly after, or if the fpga should be included in the recall as well.
 
i am late to all the forum threads about the mcu issue, but i'm trying to understand if there's a correlation between the emmc being replaced and the fpga failing shortly after, or if the fpga should be included in the recall as well.

I've only seen a handful of cases of the FPGA failing, and not always after the eMMC replacement. So I don't think the eMMC replacement is triggering it. (Not that it couldn't get zapped with static during the replacement process.) As far as should it be included in the recall, I don't think so as the recall is very specifically about the eMMC getting worn out prematurely. If it turns out to be a widespread common failure, which it doesn't currently appear to be, it might need to be a new recall. (It could be a bad batch of FPGAs chips, so limited to a small subset of Model S&Xs. Or it could just be random failures.)
 
I have a 2012 as well and had the EMMC replaced in December due to the screen going blank a few times. It was covered under the extended warranty. After getting the car back the blank screen issue didn’t come back but there were new issues such as not connecting to cellular for more than a day without a two button restart and then the nav stopped working completely with an error that the maps were not loaded. I took the car back to service and they concluded the MCU needed to be replaced. I questioned the timing after the daughter board replacement and they were patient with my questions but eventually I agreed to the MCU2 upgrade. After a few days with the car I noticed little issues that I had come to accept were resolved like no turn signal noise, garage door not always closing and connectivity issues. These were all resolved which makes me think the MCU was having issues for a while. The other improvements were noticeable as well, LTE connectivity, screen speed and resolution, stereo sound quality oh and Netflix. It wasn’t great to pay for the repair but at least the car is improved and not just repaired.
 
Last edited:
Aside from the front screen not turning on at all anymore and being black all the time, there are now bubbles appearing in the instrument cluster....

what causes this? happened overnight. does the mcu2 upgrade cover the instrument cluster too?

image0 (2).jpeg