TMC is an independent, primarily volunteer organization that relies on ad revenue to cover its operating costs. Please consider whitelisting TMC on your ad blocker and becoming a Supporting Member. For more info: Support TMC

Advice: Failed LTE/WiFi with MCU 1

Discussion in 'Model S' started by neusmell, Nov 2, 2019.

  1. neusmell

    neusmell Member

    Joined:
    Dec 16, 2017
    Messages:
    11
    Location:
    Chicago, il
    My issue is slightly different than the recent MCU 1 failures so I wanted to get some feedback from the hive mind about what's the best course of action.

    I have a 2015 Model S 90D with about two weeks left on the warranty.

    In early October the LTE and WIFI went out - it had been flaky for about a month prior (wifi not connecting/showing no bars), but the LTE still worked so I chalked it up to a bug and bad wifi connection because I live on the third floor and the weather had sucked. After it fully went out the MCU reboots constantly and sometimes just won't boot to screen (staying black for 20-30 minutes, which is my entire drive).

    Service was convinced that it was an issue with a bad update, but the mobile tech: (i) couldn't do anything without a networking card and (ii) thought that the boot issues were related to it trying to spool up the networking interface and failing for the entire 20-30 minutes.

    I finally have an appointment to go into a service center next week, so I'm not worried about the LTE card getting covered under warranty. What's going through my mind is if this is really just the LTE card and not the MCU. Does anyone have any experience with this and could say one way or another? Just want to make sure I'm prepared with questions/to pushback before the service appt. I'm really just worried that they'll say it's just the LTE card and then the MCU goes out on me a month later when I'm out of warranty.
     
  2. possum22

    possum22 Member

    Joined:
    Nov 16, 2016
    Messages:
    90
    Location:
    Mt. Isa, Qld
    Push Tesla to replace the MCU, mine lost 3G coverage when the MCU rebooted itself & reset itself & lost all settings(back to default), my car(S85) 2 months out of warranty and only 22k km at the time. WiFi on mine stilled worked.
    Make sure you turn off schedule charging or you won't be able to charge it, when the MCU finally dies. I had to trucked my car to Tesla ot get the MCU replaced, couldn't get them to do the LTE upgrade, got 12 mths/20k km warranty on thr replacement MCU.
     
  3. whitex

    whitex Well-Known Member

    Joined:
    Sep 30, 2015
    Messages:
    6,054
    Location:
    Seattle area, WA
    It could be MCU emmc dying (about the right age of the car). The problem is that reflashing the update (applying the firmware twice) may temporarily fix it, push its life just long enough beyond the warranty. Read thread on emmc dying in MCU1's.
    Likely MCU Failure (MCU1 eMMC)
    It's too late, my MCU1 Died....
    Preventive eMMC replacement on MCU1

    I'm not sure if there is any way to force Tesla to replace the EMMC under warranty if they can make it work for another few weeks or months, but you could ask.

    PS> EMMC will die in MCU2 too, as well as Model 3, except:
    1. oldest MCU2 car is ~1.5 years old today, at that age even MCU1's were ok
    2. MCU2 has larger emmc, so it will take longer to wear it out (though not necessarily proportionally longer, as MCU2 has more crapware like games and other features which take up room on emmc, plus MCU2's are getting updates more frequently - all things which wear out emmc along with logging)
     
  4. AustinP

    AustinP Member

    Joined:
    Apr 6, 2015
    Messages:
    986
    Location:
    Belgium
    I was able to supercharge after my mcu died last week, although i have scheduled charging.
    Note that I have unlimited supercharging, so it always starts without any need for mcu interaction.
     
  5. whitex

    whitex Well-Known Member

    Joined:
    Sep 30, 2015
    Messages:
    6,054
    Location:
    Seattle area, WA
    So without unlimited supercharging MCU is required to start supercharging? So all those cars Tesla has stripped supercharging are actually crippled more than people have realized, making MCU the single point of failure for one more thing?
     
  6. BPeter

    BPeter Member

    Joined:
    Feb 2, 2019
    Messages:
    460
    Location:
    Minnesota
    MCU2 also has 50% of the flash storage unformatted, so wear leveling of the writes has a massive amount of room to work with compared with MCU1. If they leave half of the MCU2 flash unused it should last as long as the car.
     
  7. NoMoGas

    NoMoGas Supporting Member

    Joined:
    Jul 22, 2013
    Messages:
    1,208
    Location:
    Los Angeles, California, United States
    Make sure you document on the service request "suspected MCU failure" and stay on top of it. Note the symptoms of MCU failure and document ON YOUR SERVICE PAPERWORK any and all symptoms you are experiencing. If the MCU does go belly up "after" warranty, you'll have an argument that it actually started to go before. They'll know what you're doing and may just replace the MCU.
     
  8. whitex

    whitex Well-Known Member

    Joined:
    Sep 30, 2015
    Messages:
    6,054
    Location:
    Seattle area, WA
    Depending how much they write. Remember that with MCU2 the updates are large (lots of bloatware like games) and logging includes videos from autopilot (fleet learning Elon has been touting) - probably things like AP disengagement and high def mapping stuff cached for when your car is on WiFi. So, while I agree that unused space helps, increased load offsets some of that advantage.
     
  9. .jg.

    .jg. Member

    Joined:
    Feb 27, 2018
    Messages:
    444
    Location:
    Weston Super Mare, England
    If the display is blank for 20 minutes and then works, it is likely that your eMMC is dying. I had exactly this issue, with MCU startups being successively longer at each startup or reset. Over a period of a few weeks, MCU booting initially took about 3 minutes but ended up taking about 2 hours. After each startup, diferent features would not work or not work properly. I am guessing that the system was performing file system checks before it could mount volumes in the eMMC and that these took longer as more elements of the eMMC failed. Ultimately, the MCU could not start at all and was replaced under warranty.
    I previously had a failure of WiFi and Bluetooth, with messages along the lines of "Initialising" or ""Device needs service". This was resolved by Tesla re-flashing the firmware of the WiFi and Bluetooth modules (remotely, via the cellular connection).
     
  10. AustinP

    AustinP Member

    Joined:
    Apr 6, 2015
    Messages:
    986
    Location:
    Belgium
    I don’t know how a car without unlimited supercharging behaves in a mcu dead case. Hence I specified my context to not generalize.

    We should have confirmation from someone with a dead mcu and no unlimited supercharging before concluding.
     

Share This Page

  • About Us

    Formed in 2006, Tesla Motors Club (TMC) was the first independent online Tesla community. Today it remains the largest and most dynamic community of Tesla enthusiasts. Learn more.
  • Do you value your experience at TMC? Consider becoming a Supporting Member of Tesla Motors Club. As a thank you for your contribution, you'll get nearly no ads in the Community and Groups sections. Additional perks are available depending on the level of contribution. Please visit the Account Upgrades page for more details.


    SUPPORT TMC