# MCU Crashing



## marcsf

So, I ran across this thread while searching for 'MCU Crashing'. I have been going around and around with Tesla service with them coming up with all kinds of possiblities saying my USB devices are causing the MCU to crash. As you can see from the text message string below, three software/firmware updats have been applied and my MCU still randomly crashes. At one point, I asked them if they are saying that Tesla doesn't support USB devices (have my iphone and SSD plugged in (Tesla Sentry)).

I have endured and endured the obfuscation and redirection with my flaky MCU. 
Has anyone out there had anything similar to this with their MCU 1 unit?

I did talk to a Tesla owner at a supercharger who talked of a flaky MCU which he said Tesla service ran him around in circles before finally replacing it. I'm assuming I'll have to endure that aslo at this point. Yes, I do know I could spend $2,500 and get a MCU 2x but not interested right now.

Here's my text history with Tesla;
2017 HW 2.5 Tesla Model S 100D about 27,000 miles
After several MCU crashes at seemingly random times, I finally logged a service request with the Tesla local shop. 
8/28/20: Requested Service for MCU Crashing
9/1/20: text - "this is Tesla virtual service regarding your touch screen concern. Can you remove all USB devices and perform scroll reset? Then see if this helps."
9/4/20: text - "this is Tesla virtual service regarding your touch screen concern. Can you remove all USB devices and perform scroll reset? Then see if this helps. Let us know, thanks."
9/8/20: text - "this is Tesla virtual service regarding your touch screen concern. Can you remove all USB devices and perform scroll reset? Then see if this helps. Let us know, thanks."
9/8/20: reply text from me: "Did that yesterday, so far will monitor it and see if it recurs. This is the third time this has happened!"
9/9/20: text - "Our tech noted: If you are reinstalling USB devices and issue is reoccurring, USB devices are more than likely causing the issue. Would recommend leaving them disconnected for a period of time to see if issue reoccurs."
9/10/20: reply text from me: "The MCu crashed three times today driving. I took photos. It occurs with and without usb devices!"
6 photos as below
9/10/20: text - "Just sent you firmware. Let us know if this helps. Reply STOP to unsubscribe."
9/14/20: text - "Tesla service here again. We see that the software update that we sent to your vehicle successfully installed this past Friday at 10:25am. Can you confirm and also please let us know how the operation of the vehicle has been since then? ---- Thank you!"
9/14/20 reply text from me: "this is the third software update and second firmware update. None of those in the past have changed the freezing/crashing of the MCU. I typically see the problem on longer drives using the navigation feature. I haven't had to use the navigation feature since last Thursday so have no idea if the most recent update changes anything. I don't typically see the freezing behavior on short non-charging trips."
9/14/20: text - "thank you for the information. At this time, we will need accurate time stamps of the concern happening again since the latest software update has been installed. We want to get to the bottom of this as much as you do but we need accurate information in order to pin point exactly what is causing the issue -- We thank you for your help in advance and look forward to you providing us new time stamps so our technicians can further diagnose!"
9/14/20: reply text from me: "you have the timestamps from the photos. Other than that, I will make note if it happens again"
9/14/20: text - "Yes, but our technicians are requesting need new timestamps since successfully installing the latest software update on Friday."
9/14/20: reply text from me: "So should I keep my appointment tomorrow or are you saying the techs need more information?"
9/14/20: text - "Your appointment is scheduled for Wednesday, September 16th, at 8:00am. We can either keep that scheduled for now to allow more time to send us some more timestamps but if our technicians do not have more data to diagnose there is not much we can do at this time. Or we could simply move the appointment back 1 week until the following Wednesday to allow for some more time -- Please let us know what works best for you."
9/14/20: reply text from me: "cancel the appointment, the next time it crashes I will document it and am requesting more than just firmware updates as this keeps happening despite now three different firmware/operating releases. The community is the hardware in this scenario so that should be the focus on the next visit which I will schedule once the issue reoccurs and is documented."
9/14/20: text - "Sounds like a plan - we will unschedule the visit for now and wait for more updates from you to diagnose."
9/23/20: reply text from me: "MCU Crashed"
photo - note that I am in reverse (left dash rear icon and the MCU is black. I was backing out of a homedepot parking space after being inside. The MCU crashed for some unknown reason. I had to do a full MCU reboot to get it to respond.









9/23/20: reply text by me: "In reverse and trying to back up and black screen", "I sent a bug report too"
10/2/20: rescheduled Tesla appointment for 10/13/20
10/8/20: text - " we sent out the latest firmware update on Oct 2nd. Can you confirm after install with no usb devices in the ports that issue repeats and if it does, use the bug report for time stamp. Let us know when you submit the bug reports."
10/8/20: reply text by me: "Are you saying that the MCU1 doesn't support having USB devices (iPhone, memory thumb drive) plugged in ?"
10/8/20: text - "No, we have seen in the past USB devices could have corruption issues that could cause issues with the touchscreen. We ask for these devices to be removed so we can eliminate that possibility for causing the issue."
10/8/20: reply text by me: "My iPhone and thumb drive causing corruption? That's a stretch"
10/8/20: text - "We are trying to figure that out. Please understand these are recommendations from our Technical team to fix your concern. If the car arrives in our shop with us not being able to reproduce your concern, we cannot perform any repair. Hope you understand we are trying to find the cause of your concern."
10/8/20: reply text by me: "Three software patches and it still crashes intermittently. I sent a bug report the last time and received no response. I will send another if it crashes again. It should be very straight forward to discern the problem from a data dump. Crash dump sent wed 9-23-30 15:30"
10/8/20: text - "The only time stamp we see is from 9/23 and 9/24 which was prior to install of 2020.36.11 and no confirmation of lack of usb devices. Have you submitted any bug reports after the 10/2 firmware update?"
10/8/20: reply text by me: "No, haven't driven much so no further bug reports yet."


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## ibgeek

Personally I'd spend the money. All you are doing at this point is going in circles and your time is worth something. On top of that, when it is resolved, you are still going to be left with an interior MCU. 
That chat above would have had my blood boiling given the run around.


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## marcsf

Yeah, agree ibgeek. I’ve been very unhappy with the run around. Hence, the reason I posted it here


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## sduck

That sounds really frustrating. However, posting it here, in a completely unrelated thread, probably won't do any good, except perhaps the good that comes from venting. It's a topic/problem that's worthy of it's own thread - if you have enough posts to start a thread, I'd encourage doing so, and you might do so in the Model S forum, the general discussion forum as it's a combination of a hardware and software problem (not to mention tesla service problem).


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## Long Ranger

marcsf said:


> 10/8/20: text - "No, we have seen in the past USB devices could have corruption issues that could cause issues with the touchscreen. We ask for these devices to be removed so we can eliminate that possibility for causing the issue."
> 10/8/20: reply text by me: "My iPhone and thumb drive causing corruption? That's a stretch"


Not a stretch at all. There have been lots of strange problems caused by the firmware not handling a corrupt USB drive well. Autopilot not working, visualizations disappearing, maybe screen crashes, I don't recall everything, most of that was last year. It often wouldn't resolve until you pulled the USB drive and let the car sleep.

You seem to have concluded this must be a hardware problem. Could be. There's also a good chance it's software. Maybe try following their advice, remove your USB devices, and if the crash occurs again give them a clear bug report with time stamp and a statement that no USB device was attached?


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## JasonF

I was one of the people who (accidentally) discovered that USB drive corruption can not only crash the MCU - but also cause Sentry Mode to sieze cameras and crash, and then throw a bunch of errors that prevent Autopilot from working until the car is "hard rebooted". The second part hasn't happened in a while - Sentry Mode still crashes sometimes, but it no longer causes camera failures.

What I would suggest is this: Buy a different brand-new high performance USB 3.1 thumb drive from a reputable manufacturer - no nameless Chinese ones - and format it using the "Format USB" on the Security settings page. They're pretty cheap these days, so it's worth a try. And also either don't charge your phone in the car during the testing period, or get a wireless charging pad. At that point you will be at a position of "standard" testing that Tesla can do internally.

Another thing that tends to crash the MCU a lot that has nothing to do with USB is Bluetooth. You might try disconnecting and re-paring your phone.


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## Klaus-rf

ibgeek said:


> On top of that, when it is resolved, you are still going to be left with an *interior* MCU.


 Inferior??


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## Ed Woodrick

Do what they are asking, remove all non-Tesla devices for a few days or enough time for them to analyze the problem. 

If it continues with the devices removed, you know where the issue is. If it doesn't, then you also know where the issue is. 

All USB things are not made equal. You may have something that has an issue. 

Just humor them to allow the issue to be resolved. Or give it to them, they will remove the devices and let it sit for a few days.


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## Bigriver

@marcsf, I have a 2017 100D model X. My MCU has always crashed a lot. For example, on a 6 hour trip it crashes at least once, and sometimes up to 3 or 4 times. I did find a sensitivity to the USB... for example, plugged into one of the ports created more of a problem than the other port. But yes, it could still crash even with nothing plugged in.

If this is new for you, is there a chance that your Emmc is dying? I've heard that the service center does have some data they can look at to see if that is on the horizon.

I agree that MCU1 is totally flaky. Much of your scenario and some of your texts with the SC are very familiar to me. I know you said you are not interested in the MCU2 change.... but I'll throw in that I did that 3 months ago and it hasn't crashed a single time since then. I'm a much happier camper now.


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## marcsf

10-13-20: text "we have run diagnostics right now on your EMMC. It's health looks good. Alerts for which indicate a failure have not been found."


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## JeffC

Agree with the recommendations to try a different high quality USB drive. USB drive corruption can definitely cause various computer problems.

Tesla has some specific recommendations in the Model 3 owners manual, for example:

USB Flash Drive Requirements for Videos and Recording To store video from your vehicle's cameras, follow these requirements and guidelines for using flash drives: • The flash drive must have a sustained write speed of at least 4 MB/s. A sustained write speed is different from the peak write speed. Check the product details of your flash drive for more information. • The flash drive must be USB 2.0 compatible. If using a USB 3.0 flash drive, it must be able to support USB 2.0. • Use a dedicated flash drive exclusively for saving Sentry Mode recordings. • The flash drive must be properly formatted. • Use a flash drive with as much available storage as possible. Video footage can occupy a large amount of space. Tesla recommends using a flash drive with at least 32 GB of storage. Some personal computer operating systems may be unable to format flash drives larger than 32 GB as FAT 32. Consider using a third party application to format flash drives larger than 32 GB. Although not a comprehensive list, Tesla has tested the following flash drives and confirmed that they meet the requirements for using Dashcam and Sentry Mode: • SanDisk Ultra Fit USB 3.1 Flash Drive • Samsung MUF-64AB/AM FIT Plus – 200MB/s USB 3.1 Flash Drive


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## marcsf

So yesteday the mobil service came to fix a bad rattle in my B-pillar which has worsened a lot. The tech said the B-pillar fascia was loose. He reset everything and took it for a drive saying he couldn’t get it to rattle anymore. That was around 8:15a. At approximately 13:44, I unplugged the car. Got in to drive to the Mall. The MCU was black but the driver display was illuminated and on. I touched the brake pedal and nothing happened with the MCU. As before, the passenger airbag icon was illuminated. I hit both touch-wheels and nothing happened. I then pressed the touch pad above the touch-wheels and pressed the brake pedal. the car display went off and then came back on. The MCU was still black. I put the car in reverse to back out with the MCU black. As I was driving about 10 minutes later, the MCU illuminated and started working as normal.

I reported it to Tesla and did a ‘Bug Report’ dump. There were NO USB devices connected when this occurred. 
10-28-20 text: "Marc, in regard to the MCU, this is a known characteristic, a scroll wheel reset should fix this issue temporarily, future firmware should fix the condition permanently. Keep the vehicle connected to WIFI when parked overnight so updates are received. Thank you for your patience."
10-28-20 reply text by me: “I have done scroll wheel resets EVERYTIME so your solution doesn't change the crashing. I posted this on the owners site and received many responses that this is NOT normal behavior.
The vehicle is connected to WiFi ALL the time at my house. I cannot say the same when I'm on the road traveling."
10-28-20 text: "Marc, the scroll wheel reset is only temporary fix as earlier stated. Having your vehicle on WIFI at your home is perfect. Not normal but it is a known characteristic and engineers are working on a new firmware release to fix that concern. Thank you."
10-28-20 reply text by me: "So this is the fourth time Tesla has stated firmware will fix the issue. Three firmware updates and still the problem!"
10-28-20 text: "Marc, we are sorry for the confusion. We are not suggesting that the very next firmware is the fix. We know that there is a fix being developed, we just don't know exactly when it will be released. From past experience, it will be sooner than later. Thank you for your patience."
10-28-20 reply text by me: "I’ve been more than patient with this. Cancel my service appointment as it appears Tesla service is unable to correct this problem. This is the last firmware update. I would like to escalate this to Tesla Customer service if this firmware doesn’t solve the problem. I have sent bug reports as requested WITHOUT USB devices. Still, I do not have a resolution for this despite three prior promised firmware update fixes."


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## JasonF

A recent issue I had might help you:

I tried swapping a USB stick for a tiny USB SSD. It crashed the MCU, twice, before I discovered the cause was that the passenger side front USB port wasn't working correctly. Mobile service is coming Friday to deal with it.


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## Bigriver

It's a 2017 model S, but how long have you had it? I think it is important to know whether this is a new behavior for the car or if it has always done this. As I noted above, my MCU1 always misbehaved. And MCU1 will eventually crash and burn because of too many write cycles on the eMMC. Have you had discussions with them on the health of your eMMC?



Bigriver said:


> https://teslamotorsclub.com/tmc/thr...thread-mcu-repair-black-center-screen.181124/
> More than you probably ever wanted to know on the subject.


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