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2020 Model SL LR, running 2021.4.12: MCU freezing, requires scroll wheel reset - anyone else have this problem?

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gbailey

2022 Model S LR
Oct 9, 2019
268
239
Arkansas
As above, is anyone else experiencing this problem? It’s happened 3 times over the past week. Always when returning to the car after it’s been parked for a few hours. I use PIN to drive so this is an issue. Should not be hardware with a car that’s just over a year old. Tesla have cleared the MCU cache and forced a reinstall of the latest software which has made no difference. Car is a 2020 Model SLR, HW3, MCU 2, FSD.
 
Have you notified Tesla? I suspect it’s a software not a hardware issue but hoping it will be resolved soon.
No I haven't. It's a pain to deal with their support for issues like this in my experience (they want to walk you through their entire playbook before they actually send a bug report to engineering). I'm fairly certain that it's a software issue because it started after I had done one of the recent software updates (2021.4.3, I believe). It may be related to the bug that prevents the car from sleeping when plugged in (as discussed in another thread), because I haven't had the frozen screen since I leave the car unplugged in the garage.
 
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I had the car reboot itself at least twice on 2021.4.11 and the same on 2021.4.12. I got in the car and it was fine after the update. Drove somewhere, when I came back the screen was black, then rebooted. Also, after getting out the car at home, between the time I shut the driver's door, and when I went to plug in, the charge door would not open from the button on the UMC. I pushed the door and it opened, then I noticed the screen rebooting.
 
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I had the car reboot itself at least twice on 2021.4.11 and the same on 2021.4.12. I got in the car and it was fine after the update. Drove somewhere, when I came back the screen was black, then rebooted. Also, after getting out the car at home, between the time I shut the driver's door, and when I went to plug in, the charge door would not open from the button on the UMC. I pushed the door and it opened, then I noticed the screen rebooting.
Thanks. I haven’t had the issues you describe but have had the screen freeze. I’ve just reported it again to Tesla service, this time with a time/date stamp. I suspect we’ll get these issues resolved through a future software update.
 
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I was constantly having MCU problems such as yours and had logged all of them so i could report it to Tesla. Eventually, i called for support and a tech came out. The solution was a hard reset. Note that when we push the two steering wheel buttons, that's a soft reset. A hard reset is when you unplug the 12V battery from the main battery by lifting the back seat and decoupling the plug and then taking the cables off the 12V battery. After waiting a minute, he reconnected the cables and the software rebooted. i've just had one screen freeze since then, which is a substantial improvement.
 
I was constantly having MCU problems such as yours and had logged all of them so i could report it to Tesla. Eventually, i called for support and a tech came out. The solution was a hard reset. Note that when we push the two steering wheel buttons, that's a soft reset. A hard reset is when you unplug the 12V battery from the main battery by lifting the back seat and decoupling the plug and then taking the cables off the 12V battery. After waiting a minute, he reconnected the cables and the software rebooted. i've just had one screen freeze since then, which is a substantial improvement.
Thanks, that’s good to know. It seems that my problem may be connected to the Roadie (a raspberry pi-based device that allows me to access dashcam footage remotely). In addition to the MCU freezing I also had errors on the driver display that a device plugged into one of the USB ports was not working. It maybe that it was drawing too much power or not allowing the car to sleep. In the past few days I’ve replaced it with a standard high endurance usb card and now the car is sleeping with no screen freezes. I’ll report back if this fixes the issue.
 
Ah! the front USB ports only provide 1A of power, which is not a lot. If you use splitters and plug multiple things, you might overload them, and the plugged devices could misbehave as a result. Using a "computer" (rPI) or an SSD, which a lot of people do, stresses this as the power demand is quite high. I have a hub (Jeda maybe?) that I believe combines the power from both ports and has its own controller. I think that helps. Still, be careful what you plug up front as the MCU communicates with the devices for music, dash cam etc.
 
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