Model S

What is Tesla doing about eMMC failure on MCU1 units?

I have an out of warranty 2015 model S, that just got the black screen on the MCU, while getting the software update. I opened up a service call for next week, but I am hearing that Tesla replaces the whole MCU for $2,500. This is going to be overkill for a chip replacement. How can I get in touch with Tesla (and not the local shop) to discuss this outrages price, especially when I just paid $1,000 3 months ago for a leaking screen on the MCU?


  • Charging you $1500 to replace MCU1 or upgrade for $2,500

    You can call 1 (877) 798-3752

    I would contact service to see if they can help with the pricing since you just had it repaired.

    Their email is usually [email protected]
  • Also, it sound like the MCU1 you had replaced is still under warranty. There should be no charge to replace.
  • The $1,000 was just for the liquid screen replacement, not the whole MCU, but I will be bringing that up when I talk to someone.
  • @peterlopes, recent reports (today) on this forum tell us that you can get just the Tegra board inside the MCU replaced for less than $1,000

    And we also just heard (today) the price on the MCU2 Upgrade is now $1900 including labor.

    Now, that I have given you good news, can you share with me a little about your car, please?

    Battery size?
    Car's Build date?

  • Miles:63,000 miles
    Model: 70
    built: Oct 2015
  • They replaced the MCU1 daughterboard in my 2015 Model S last week for $957. It seems to be working OK except the Nav maps are not downloading. They are working on that remotely.
  • @akikiki, all due respect, but in pushing the MCU2 "upgrade" it needs to be loudly disclosed this means forever losing AM/FM and SXM (if supplied). IMO, Tesla boned this badly, when with a bit of engineering they could have truly made it an ugrade: current functionality PLUS new functionality.
  • rxlawdude, you are correct. I would if I were on a commission. So, therefore, but, however, instead, I guess, you can, 'cause "not my yob" :) Most respectfully as I can conjure up.
  • The MCU2 is not currently available for some cars. The Service Center told me that 2015 cars had to have the Premium package in order to have the correct wiring harness for MCU2. I did not order that package so MCU2 was not an option for me when the MCU went out.
  • Recently saw on Facebook the daughter board is being replaced for less than $400. My service manager is the area somewhat verified this information.

    Personally I am very disappointed learning of this. The daughter board removal did not just appear out of nowhere. I mentioned this long ago on here as to why Tesla charges to replace the whole unit when they can just replace the board.

    This repair was simple and cheap after they charged owners $4k at one point (now $2k for whole unit and dropping due to class action suit) and then turned around and refurbished it for dirt cheap. They then resold the broken unit as refurbished for an insane amount of profit margin.

    I thought they said the service centers are not profit centers...
  • Silver - you should know by now, Musk lies a lot. And the kicker is they re[place it with the same flawed design, so you can repeat and rinse in a few more years.
  • I'll add my stats to the list since my MCU1 went out a week ago after reboot (was stuck downloading 2020.24.6.11 for weeks), scheduled an appointment through the app which later got converted to an in-service center appointment in Fremont. This is my second MCU to go out.

    2014 S85, built 9/14, 121k miles, (was) running 2020.20.1. First MCU replaced under warranty 11/15.

    It currently won't Supercharge, but will charge at home via 120V outlet if climate control is running. If I try a public L2 charger, it maintains L1 speeds (212V, predictably fluctuates between 3 - 7 amps). At home where the UMC is connected to the smart plug I can see the energy pull bounce between 600 - 1250 Watts. In other words, assuming I don't drive the car and keep the car charging with the climate on, I net even on SoC. But if I don't charge it I lose maybe 2 - 3% a day. I hope the battery will have enough charge to make it to the service center next week.

    Cruise control and radar work, no ultrasonics. Autosteer will max at 45mph. Vehicle doesn't lock itself upon walk-away nor do handles auto-present when near.
  • @mybluetesla, I am sorry to hear about your MCU. Thanks for the info. Got it, and had your first one too.
  • @mybluetesla
    I had a similar situation where my garage 30A plug maintained the heater loss, which was stuck on, but charge could not be added to the battery. So my SOC remained unchanged over 16 days.
  • I think heating in winter and cooling in summer will stay on by default to protect the pack and other components. Itried controlling the system through the steering wheel, but no go. The system is programmed to go into auto mode and disable your input from what i have observed.

    When my screen failed in July the ac stayed on auto level 1 and when I started driving it ramped up.
  • Forgot to add, I was able to supercharge and charge at home. I did not have the issues some of you had.
  • @Silver2k - Two weeks ago they repaired my MCU1 by doing the daughterboard replacement. The total cost was $957. The part was $500. It was going to cost $380 to attempt to recover stuff off of the dead MCU1. That did not work so they only charged 1/2.
  • CA,

    I find them charging you half incredibly odd. The installation and recovery is 2700 for my upgrade, but did not refund me anything when they couldn't recover my data.

    The quote and end price was exact and I didn't get the data.
  • This paints a picture of chaos at the service centers.
  • It's a top-down issue.
  • For those complaining about Tesla now having this fix of replacing the circuit card vs the whole MCU are either forgetting or are not aware of the fact that back when there were noise issues with the original DU’s, they outright replaced the whole DU’s because the service centers did not know or were not equipped to do the needed repair. Then after some time, the service centers were able to replace the bearings in the motor.

    Yes, I know that was all under warranty, but I am speaking to the notion that Tesla could have/should have done this card swap from the get go. Well, it is quite logical that the engineers in CA had to come up with one, a supply of replacement cards and two, create a repair procedure that could be done by the service centers.
  • JR

    The repair is very simple and the daughter cards would without a doubt be available. You can get any non-tech to remove that card. And the fact that it is a daughter card and not soldered directly to the mainboard tells me they knew if they would have had this issue in the future, the card can simple be replaced instead of the whole board.

    Tesla knew they can charge what they want, because no one else had this equipment and must replace it to continue enjoying their tesla.

    If not true, then why have the daughter card?
  • The CPU daughterboard was designed and manufactured by Nvidia as a single part and sold to multiple companies, not just Tesla. This likely reduced costs, as Tesla volumes, back then were tiny as compared with other manufacturers.

    Tesla designed in the Nvidia board as a single part. It saved development time and engineering resources, back in 2010 when Tesla was tiny compared with other carmakers at the time.

    It's not even clear that Nvida was willing to sell the CPU chip as a stand-alone part that could be installed on your own motherboard. So if you wanted to use that CPU part, you likely had to buy their CPU daughterboard. The CPU chip was quite advanced for the time - a quad-core design with special low-power modes ideal for vehicles where you had high-performance needs while driving, and low-performance needs when parked and the car is not in use, but still needs some processing.

    Ok, likely more than you wanted to know :)
  • I would guess Nvidia back then and today would be more than happy to sell the daughter board. Nvidia is a bigger company and a more profitable company today. Why would they sell the part now, but not when they were smaller and needed cash flow?

    The daughterboard was/is not new tech, this tech has been in laptops and other systems for a very long time.

    I care about this company as much as anyone else, but right is right and wrong is wrong.
  • The Nvidia CPU design is now over 10 years old. I'm sure it went out of production years ago. The tiny repair and replacement market often doesn't warrant keeping an obsolete part in production. It's a negligible part of Nvidia's market. I'm sure they would much rather sell a newer/faster and more expensive part.

    I see this all the time in the industry. I've had parts discontinued that we were using in volume and had to scramble to get what remaining parts were available and then rush through a redesign. Sometimes you get 6 months warning, but not always. Maybe the production was problematic, or they shut down the chip's production process to go with a finer line width for newer parts.

    The eMMC chip made by Hynix on the board was also discontinued about 3 years ago, but there are newer alternatives. I suspect part of the reason it was discontinued was the problems that started to show up.

    Technology moves ahead at such a rapid pace. I'm sure it's one reason Tesla designed the MCU2. I expect in 5 years we'll see an MCU3, as MCU2 parts become obsolete and out of date.
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