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Will Tesla Warranty-Replace MCU1 when Failure Symptoms Start?

Dec 26, 2018
525
410
TX
Hi Folks,

My 2016.5 MCU1 car is starting to show early signs of MCU failure.
  • The screen randomly stays black for up to 5 minutes at startup (even though it's on 'always connected')
  • The control menu is glitchy and sometimes does not load images/buttons
  • Maps take a long time to load, and sometimes it loses connectivity for long periods
I get the feeling it's soon to fail. My car is under warranty (3 years left, bought 'cpo').

I have a mobile service ticket open for this weekend to have it investigated, but I don't imagine they will do a mobile MCU replacement. My question is: Will Tesla proactively replace the MCU under warranty if it's showing signs of imminent death, or do they wait until it black-screens permanently? I've read that the lead time for a replacement can be months, and that amount of time without HVAC in south Texas sounds....bad.
 

markb1

Active Member
Feb 17, 2012
3,052
659
San Diego, CA
I think it depends on if they can fix the symptoms or not. I just got my car back from the service center, after the MCU went offline. They were able to revive it, so they did not replace it.
 
Dec 26, 2018
525
410
TX
Thanks folks, that's good news. I could just see it dying and taking the a/c with it while I'm trying to take a customer to lunch or something...that would not end well, especially since I'm in Oil Country and they're already looking for any excuse to knock on EVs!

I'm not sure if mine will be revivable in the long term - anything they'd do wouldn't change the fact that the memory chip is likely near the end of its re-write limit. But I'm curious what mobile will find this weekend.
 

markn455

Member
Apr 8, 2016
371
144
Ball Ground, GA
They would not replace it for me. They cleared the cache, cleared the trip odometer, and said everything is fine and they have not seen any failures on the later MCU1s. BS, mine is continually causing issues. Tesla is a delay, delay, delay. Now I am out of warranty and telling me that if I want to correct the issue, I have to upgrade to MCU2. grrrr
 
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Reactions: aerodyne
Dec 26, 2018
525
410
TX
They would not replace it for me. They cleared the cache, cleared the trip odometer, and said everything is fine and they have not seen any failures on the later MCU1s. BS, mine is continually causing issues. Tesla is a delay, delay, delay. Now I am out of warranty and telling me that if I want to correct the issue, I have to upgrade to MCU2. grrrr

i got the same answer - clear all my saved stuff and monitor.
Never had a $100k car whose trip odometer caused an issue with its functionality.....
 
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TechOps

Member
Jun 4, 2017
210
238
Austin, TX
They would not replace it for me. They cleared the cache, cleared the trip odometer, and said everything is fine and they have not seen any failures on the later MCU1s. BS, mine is continually causing issues. Tesla is a delay, delay, delay. Now I am out of warranty and telling me that if I want to correct the issue, I have to upgrade to MCU2. grrrr

Same here, I didn't ask for a replacement but just had it addressed by the service center. They "freed up space" on the MMC, and the MCU was more responsive and working better... until a couple days later when it spontaneously rebooted itself 2 or 3 times in a row while driving.
 
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appleguru

Member
Mar 15, 2017
952
1,688
US
Latest from my local SC:

Our team had identified the issue related to you MCU due to /tmp directory is filling up due to a regression with dashcam. There has been improvements with version 2020.36.11 with a future firmware fix to come.
 

markn455

Member
Apr 8, 2016
371
144
Ball Ground, GA
The MCU has to completely fail screen goes black and will not come back up, then they will replace it under warranty. They will not replace it based on poor performance and unexpected behavior.
 
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beatle

Active Member
Aug 31, 2019
1,164
608
Springfield, VA
Mine was replaced with the screen still functioning. It had numerous problems, however. It no longer worked with the app or API, and reboots took about 3 hours. The trip odometer also stopped functioning, and I could no longer stream music. Navigation still worked which was interesting since I thought it required a network connection.
 

markn455

Member
Apr 8, 2016
371
144
Ball Ground, GA
Mine was replaced with the screen still functioning. It had numerous problems, however. It no longer worked with the app or API, and reboots took about 3 hours. The trip odometer also stopped functioning, and I could no longer stream music. Navigation still worked which was interesting since I thought it required a network connection.

I am sure there are exceptions but generally speaking the Service Center will not replace unless the screen goes black and will not come up. Typically the reboot takes 4-5 minutes. Perhaps since the screen stayed black that long, it certainly qualified.
 
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JohnQ

Active Member
Jan 1, 2012
1,612
75
Redding, CT
Mine was replaced with the screen still functioning. It had numerous problems, however. It no longer worked with the app or API, and reboots took about 3 hours. The trip odometer also stopped functioning, and I could no longer stream music. Navigation still worked which was interesting since I thought it required a network connection.
Navigation is still onboard and will display on the IC as long as you have a GPS connection. Center screen navigation requires a network connection to update tiles. Eventually you drive off the cached map.
 

AlexP

Member
Nov 13, 2018
109
30
Miami, FL
I believe that the MCU 1's in my S and X will be failing soon. They have been rebooting by themselves. A couple of weeks ago the one in the X did not turn on. I had to reset it with the steering wheel. I made an appointment and the mobile tech said in the ticket that he re-flashed the FPGA (Field Programable Gate Array) and that if the problem persisted to continue making service appointments.
 

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