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Suspect MCU is dead and mobile connector "locked in", need advice on next steps.

Discussion in 'Model X' started by MXWing, Dec 8, 2019.

  1. MXWing

    MXWing Well-Known Member

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    USA
    A few days ago, my wife was driving the inlaw's X with a blacked out MCU screen. Once I took a look at it, I rebooted the MCU.

    It took awhile to come back up and I thought the matter resolved.

    Today I went to check into the car and found out I could not access it remotely. it says its been offline since the day there was the blacked out MCU issue.

    The vehicle does not respond to the keyfob button pushes nor does it respond to the physical door buttons with keyfob present.

    I am thinking a tow to a service center is not the only option? Another issue is the mobile connector is locked in place. It's not performing any charging.

    Any insight or advice from anyone who has seen this issue would be appreciated.

    Thanks!
     
  2. EldestOyster

    EldestOyster Member

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    Is anything working on that car? It sounds dead the way you explained it. A jump start and a new 12V battery might be in order.
     
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    • Like x 1
  3. boaterva

    boaterva Supporting Member

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    Northern Virginia, USA
    Does it respond to the app at all? Understand you may not have access since it’s not your car but sometimes they wake up from there when dead locally. This worked when we had a failed install and had to reboot it. Worth testing the charger port unlock or other functions.
     
  4. Newscutter

    Newscutter Member

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    Pure speculation... But could be the MCU died, which would prevent charging if the "scheduled charging" option was selected. It has also been reported that, depending on config, a dead MCU can lock the HVAC on to maintaining whatever temperature it was last set at even when it would normally be parked/powered off. That would drain the main pack and below a certain level the main pack doesn't charge the 12v... and thereby draining the battery and basically bricking the whole car in place since the X door releases require power.

    If you can gain access to the 12v, you should be able to revive enough functionality to get into it, but with a dead MCU I don't think you have any way of getting it into tow mode and without being able to disable scheduled charging (assuming it's on) there's no way that I know of get power into the main pack without replacing the dead MCU.
     
  5. MXWing

    MXWing Well-Known Member

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    I reached out to Tesla mobile service team and described the symptoms.

    I was then asked to call road side service.

    Dispatch said it was a dead 12V.

    Dispatch wondered why I didn’t notice the 12V warnings?

    Dispatch then confirmed that the warning happened minutes, hours maybe before it went out.

    The suspected resolution was to send out a tow truck.

    Driver jumped the 12V and I’m on a ride to Tesla.

    Annoying that warning didn’t happen sooner. However am glad car was not on a road trip when this occurred.

    To Tesla’s credit, being on a tow truck within 45 minutes of my first call is amazing. All this in the highly impacted so cal market as well.

    Will update if I hear anything interesting beyond a 12v swap.

    Thanks for the help everyone!
     
    • Like x 1
  6. Xminus6

    Xminus6 Member

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    Interesting. I had the 12v warning recently and I didn’t take it in to get serviced for a couple weeks. Same thing happened a couple years ago on this same car but they did a mobile service replacement of it. But the warning was showing for at least a couple weeks. Wonder if something was left on in the car to drain it that quickly.
     
  7. jgrgnt

    jgrgnt Supporting Member

    Joined:
    Dec 13, 2016
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    Location:
    Orange County, CA
    Yikes. I've had the 12V warning for a little over a week, with just a few days to go before my scheduled appointment. Hope it makes it!
     

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