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Padelford

Member
Supporting Member
Jul 1, 2017
668
632
Seattle
This morning, I was greeted with a completely blank, dead MCU1. It had been working fine but sluggish yesterday, but two-scroll-wheel reboots have been taking more than two minutes before today. I tried the reboot this morning, gave it three minutes and gave up. The vehicle took 1-2 minutes to wake up enough to drive after pressing the brake pedal (usually instantaneous), and when I tried to drive it to a service center, it initially refused to recognize the key fob even when it was placed in the back of the center console. The car did finally accept the key fob after a few minutes, but it was a long "few minutes".

BTW, if you haven't heard this, the two-scroll wheel reboot procedure has apparently changed. One no longer has to hold the scroll wheels down until the Tesla logo appears. The scroll wheels can be released as soon as the MCU screen goes blank. I hadn't heard about this. Also, holding down the brake pedal with the scroll wheels does nothing extra - they've been telling people to do this just for extra safety. I naively thought the brake pedal meant a different, deeper reboot.

I called the tech support number twice during this episode. The first time, the agent was able to download data from my vehicle and thought that the MCU was working, but she simply didn't have any technical understanding of what she was seeing. In the past, the agents I've dealt with had some working knowledge of the Tesla software and could do more to help.

She told me to schedule a mobile service to get the MCU problem fixed ASAP, but I already have a service center appointment scheduled for 9/9/20. It turns out that the app will not allow an additional appointment of any kind unless the current one is cancelled. The agent knew I already had an appointment, so she wasn't aware of the app limitation. I called the tech support line again, and the second agent told me to take the vehicle to the local (Renton) SC as a walk-in and they would help me.

They did take the vehicle in, but I was told later by text that it wouldn't be done until next Thursday (9/3/20). That's a lot longer than I expected. Somewhere in between now and then, I assume/hope they'll contact me about what's wrong. The Renton SC appears to be overloaded with work - there was a technician outside in the driveway working on a M3 on jack stands.

While driving back from the SC, I realized that my 2013 Audi Q5 had served as a shuttle vehicle for Tesla service way more often than my MX has served as a shuttle for Audi service. <Sigh>
 
BTW, if you haven't heard this, the two-scroll wheel reboot procedure has apparently changed. One no longer has to hold the scroll wheels down until the Tesla logo appears. The scroll wheels can be released as soon as the MCU screen goes blank. I hadn't heard about this. Also, holding down the brake pedal with the scroll wheels does nothing extra - they've been telling people to do this just for extra safety. I naively thought the brake pedal meant a different, deeper reboot.
I've seen this alleged recently, but I've also seen differing behavior historically. For instance:

1) I've NEVER held the two scroll wheels until the Tesla logo appears to reboot unless I'm ALSO holding the brake while waiting for the Tesla logo.

2) When I release the two scroll wheels after the screen goes black as normal, the Tesla logo SELDOM appears during the reboot process.

To me, this makes it look like holding the scroll wheels and brake would be necessary for a deeper reboot in spite of some people insisting otherwise (my assumption was that this design prevented a deeper reboot during driving). On the other hand, if you always held only the two wheels until you saw the logo and always saw it, that does support the suggestion that the brake could just be for safety. In any case, I also wonder if it isn't different for MCU2. It's also feasible that some update changed the behavior to always do the deeper reboot so that holding the scroll wheels was no longer necessary.
 
I've seen this alleged recently, but I've also seen differing behavior historically. For instance:

1) I've NEVER held the two scroll wheels until the Tesla logo appears to reboot unless I'm ALSO holding the brake while waiting for the Tesla logo.

2) When I release the two scroll wheels after the screen goes black as normal, the Tesla logo SELDOM appears during the reboot process.

To me, this makes it look like holding the scroll wheels and brake would be necessary for a deeper reboot in spite of some people insisting otherwise (my assumption was that this design prevented a deeper reboot during driving). On the other hand, if you always held only the two wheels until you saw the logo and always saw it, that does support the suggestion that the brake could just be for safety. In any case, I also wonder if it isn't different for MCU2. It's also feasible that some update changed the behavior to always do the deeper reboot so that holding the scroll wheels was no longer necessary.
Since my MCU2, the Instrument Cluster (IC) reboot is tied to the Main Screen thumbwheel reboot, that's a welcome change.
 
Since my MCU2, the Instrument Cluster (IC) reboot is tied to the Main Screen thumbwheel reboot, that's a welcome change.
Well... With MCU1, the IC was a separate computer. With MCU2, it isn't. Previously you could reboot the IC by holding the two buttons above the scroll wheels. Now if you lose the MCU while driving (due to a crash or reboot), you will lose the IC, too.
 
Epilog: I got my vehicle back this afternoon with MCU1 working again. Here's what was on the work order:

Concern: Customer states the Touchscreen is blank and Scroll roll reboot did not help.
Technician verified MCU was blank at time of service. Performed a gateway reset and MCU and was able to bring MCU
back online. Updated the vehicle firmware twice and verified MCU is operating normally at this time.

The MCU seems to work the same as before.
 
I have an 2017 Model X 100D and recently I have noticed that my MCU1 is crashing a lot for no apparent reason. I see some posts suggesting that MCU2 will also crash/reboot. Recently I had a service appointment reporting that my internet page refresh with good signal is almost unusable. They are suggesting an upgrade. I said, "You want me to pay for an upgrade to get the functionality you sold me?". No resolution yet except that I have common crashes and I cannot use the internet browser. Has anyone else dealt with this. I suspect that the firmware has gotten more "bloated" over time the the MCU1 Processor cannot keep up with the demand.
 
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Well, my MCU went bonkers again this morning with a blank screen but I could hear sounds like a hard drive being accessed. I did the two-scroll-wheel reboot, and saw the backlight come on but still a blank screen. I started driving, and after some minutes, the Tesla "T" finally appeared. It still took a few minutes to completely boot up to normal, significantly longer than in the past.

After the MCU rebooted, I blew away the trip odometer B reading which was a bit large, and cleared out all the Nav destinations except for five or six.

For some reason, the MCU fails after the vehicle has sat overnight. I haven't observed a failure while driving. As I recall, there used to be a user-defined setting under Controls for a "deep sleep" option. I can't find anything like that now (2020.36).

I put in the request for the upgrade on the Tesla app, and they claim 30 - 60 days for the parts.
 
An update: my MCU completely died shortly after I posted the above message. I’ve got a SC appointment for Oct 1st, and I have not yet been contacted about the appointment.

I’ll post more as this develops.
 
Pretty standard to not have any communication until about a day or two before the appointment.

I sincerely hope they contact me well before the appointment. The vehicle is unable to communicate on-line status, so I'm expecting Tesla to be skeptical of what's wrong. I'm expecting to get at least an MCU1 replacement under warranty, and I don't want to have to wait another week or two for that after the SC visit for hardware availability. I've stopped driving the vehicle.

in principle, since they told me the "fix" they implemented on the first failure was only temporary, they should have ordered a new MCU1 at that time.
 
Next chapter: the vehicle will not start up. The center display comes on, the vehicle obviously recognizes the keyfobs by unlocking the vehicle, reacting to the top button with horn and flashing turn signal lights, but the vehicle will not start up to be driveable. Placing the keyfobs in the cup holder, or below the cup holder, yields the same result. No error messages about "key fob not in vehicle".

The vehicle previously once showed some fussiness when the MCU died about recognizing a key fob but showed an error message, "Key fob not in vehicle". At that time, I managed to get the vehicle to recognize the key fob and was able to drive. Not now.

The vehicle still charges.

I called Tesla, and they're sending out a tow truck tomorrow to pick up the vehicle and take it to the Renton SC. I'm VERY GLAD I followed my gut instinct and left the vehicle parked at home since the MCU died. I highly recommend others experiencing a dead MCU do the same or face being marooned somewhere unexpectedly. The person on the phone suspects the 12V battery may also have died, but since the vehicle isn't completely dead, I doubt this is true. She said she's getting a lot of calls lately about 12V batteries dying without warning. She also told me not to connect the vehicle to the charger in case it can't be disconnected tomorrow before the tow.

More tomorrow about what they have to do to get the vehicle on a flat bed with a dead MCU and no easy access to set Tow Mode.
 
Next chapter: the vehicle will not start up. The center display comes on, the vehicle obviously recognizes the keyfobs by unlocking the vehicle, reacting to the top button with horn and flashing turn signal lights, but the vehicle will not start up to be driveable. Placing the keyfobs in the cup holder, or below the cup holder, yields the same result. No error messages about "key fob not in vehicle".

The vehicle previously once showed some fussiness when the MCU died about recognizing a key fob but showed an error message, "Key fob not in vehicle". At that time, I managed to get the vehicle to recognize the key fob and was able to drive. Not now.

The vehicle still charges.

I called Tesla, and they're sending out a tow truck tomorrow to pick up the vehicle and take it to the Renton SC. I'm VERY GLAD I followed my gut instinct and left the vehicle parked at home since the MCU died. I highly recommend others experiencing a dead MCU do the same or face being marooned somewhere unexpectedly. The person on the phone suspects the 12V battery may also have died, but since the vehicle isn't completely dead, I doubt this is true. She said she's getting a lot of calls lately about 12V batteries dying without warning. She also told me not to connect the vehicle to the charger in case it can't be disconnected tomorrow before the tow.

More tomorrow about what they have to do to get the vehicle on a flat bed with a dead MCU and no easy access to set Tow Mode.
When my MCU1 black screened, it could still charge, but blinkers non-functional. This made the car un-safe, so I got put to the front of the line for infotainment MCU2, and got it. Just do this if you wanna put your problems behind you.
 
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When my MCU1 black screened, it could still charge, but blinkers non-functional. This made the car un-safe, so I got put to the front of the line for infotainment MCU2, and got it. Just do this if you wanna put your problems behind you.

Did this happen while you were still under warranty? I'm wondering if I can bargain on the cost of MCU2 given that they at least owe me a new MCU1 under warranty, which appears to cost at least $1300.