My MCU is dead, cannot turn off heat or close sunroof. Replacement part: "possibly a few weeks"

[pacmanbrodude]

I have been having phone app connectivity issues which lead Tesla service team to believe my MCU was dying. It has been months since my app was able to connect to the vehicle. Sure enough, the day before scheduled to take it in, we had the sunroof vented and were poking around at the fireplace mode when boom - the screen went black. The MCU died. No amount of scroll wheel asphyxiation + brake pedal would bring her back. (when you're resetting the MCU, am I the only one who feels like you're suffocating someone with a pillow?)

After dropping off Teslato to the Service Center, they confirmed that the MCU would need to be replaced. I had hoped that MCU 2.0 would be an option, but it looks like Tesla is late on their estimated release of that. It's changed from "Early April" to "Coming Soon". I asked the service rep and they confirmed it's not available at this time, and gave no inkling or glimmer of hope for when it's available.

So they notify me my parts have been ordered and it is ready to come pick it up.

Can you tell me if you were able to shut off the heat and close the sunroof? I'm not sure if it's best to take possession of my car in this state if they were unable to close the sunroof or turn off the heater

We were not able to shut off the heat nor close the sunroof. Wish we could have​

Really, that's not good. There's no way to fix that? What about disconnecting the 12v battery?

The MCU is not a serviceable part. after all the diagnostics run, we are confident it needs the MCU replaced. We prefer not to have your car on the lot for, quite possibly, a few weeks before the part arrives.​

So I'm going to have my heater on high for possibly a few weeks.
Can you pull a fuse out? I hope you can empathize with how unideal this is.

When I arrived to pick up the vehicle, the gentleman behind the counter passed off my keys to me, and looked like he really hoped I would not have any followup questions for him. He said he had his best technician working on the car all day, and they couldn't resolve the problem. They expected me to take my vehicle home, sun roof stuck open, heater on HIGH, for likely a few WEEKS. As politely as I could, plead with him further, and he consulted his technician again. It completely blows me away that the service center cannot disable the heater or close the sunroof manually. What if I let the battery run down to zero to prevent the heater from staying on? No that would likely damage the 12v battery, he says.

He came back with the suggestion that they can have mobile service come out when I get home to completely disable the car to stop the heater from running (and the rest of the car as well). They scheduled this to happen, 6 days later. Debating on cancelling and just not driving it when it rains and keep charging it every other day just so I can have a vehicle.

I love Tesla probably more than I should, but this is frustrating. Not to mention the car is now out of warranty and I'll be paying for this all out of pocket. I'm debating on waiting for the MCU 2.0 to be available - at least I won't be throwing $1600 at old hardware, and instead $2500 at an upgrade. At least the price for the repair seems to have come down - others I've seen around were $2500-$3500.

Sooo.. does anyone know how to manually close a sunroof or kill the heater with a black screen and no phone app connectivity?

 

[BPeter]

Disconnecting the fireman's loop should completely shut off the car.
But to get to it you're going to need to do the manual hood release.

 

[PrGrPa]

‘A few weeks. Definitely by end of year’?

joking aside, this sounds like a real pain. In the absence of a spare part I’m surprised that there isn’t a temporary workaround where the MCU can be unplugged and emulated by a laptop or phone. At least to control essential functions.

still, given the importance of the MCU to so many day-to-day operations I’m not sure I’d want to drive the car anywhere without it working.

 

[EV-Fixme]

You should be able to shut off the heat by pulling the fuse for the MCU, then putting it back in. There is no easy way we know to close the roof. Yes your eMMC is likely dead, but the key files might be recoverable still. We provide free diagnostics of the emmc for just the cost of shipping, we can offer it completely free for drop off, but you will likely want to ship if your interested. Tesla does not service inside of mcu outside of modem upgrade. We can offer service.

The fuse information is on our page. http://evfixme.com

We can also help you with 3rd party repair of eMMC with roughly a 1-2 week turn around.

 

[pacmanbrodude]

Disconnecting the fireman's loop should completely shut off the car.
But to get to it you're going to need to do the manual hood release.

The key fob still is able to open the trunk. First I'm going to try the MCU fuse. If I can't get the heat off, then I'm going to try disconnecting both the fireman's loop and the 12v battery. If I'm understanding others correctly, disconnecting the fireman's loop but not the 12v battery would cause the 12v battery to completely drain and be damaged.

Ideally Tesla would have the MCU 2.0 ready for older cars, but I think I'm going to go with EV-Fixme's services.

 

[pacmanbrodude]

An update. I didn't attempt pulling out the fuse, but I disconnected the 12v and high voltage battery for about 2 hrs while disassembling the trim to get to the MCU to send the Tegra board out for repair. When I reinstalled the MCU and connected the 12v/high voltage battery, the climate control heater which was stuck on high (with a black screen, no mobile app connectivity and no way to turn it off) did not turn back on.

Sunroof is still stuck open though.

 

[pacmanbrodude]

@EV-Fixme Thank you, I had a success story using this third party vendor. Pretty quick turnaround too. 9 days, shipped across the country. Only thing so far as I can tell that wasn't recovered was my trips.

 

[SSedan]

Thank you for sharing your experience.