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MCU died, AC won’t turn off... vampire drain excessive

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Driving much less now obviously. Went to drive it yesterday afternoon for the first time all week and the MCU won’t turn on.

The car still drives and still connects via the app, but the vampire drain is excessive as the A/C won’t turn off. Attempts via the app are unsuccessful.

I have a scheduled service appointment for Thursday morning, but is there any other way I could get the A/C off and whatever else may be draining the battery?
 
Can you change the function of the right scroll wheel to fan speed and set the fan to zero?

That would at least provide some possible feedback unlike a scroll wheel reset which wouldn’t have any feedback at all with a broken MCU.

I should’ve mentioned that the right scroll is set to sunroof and while it will show a signal to open if I scroll, the sunroof doesn’t actually open.

I did try your suggestion. It displays the current fan speed (5; auto) it doesn’t even pretend to change the fan speed setting. Ditto temperature.

Also meant to mention that I’m in a 2014 P85D
 
You can pull the cubby out below the MCU, (pull straight downward with a fast jolt), then reach behind the MCU an you’ll feel three large wiring harness clips. Unplug the middle one which contains power. That should cut power
Pulling the MCU fuse might be easier and accomplish the same thing - power off the MCU, see if that shuts off AC and if not, try to power MCU back on by reinserting the fuse and if AC shuts off during boot, pull the fuse right there and then to keep it off.
 
Pulling the MCU fuse might be easier and accomplish the same thing - power off the MCU, see if that shuts off AC and if not, try to power MCU back on by reinserting the fuse and if AC shuts off during boot, pull the fuse right there and then to keep it off.
Guaranteed pulling the MCU power plug is easier.
 
Went to the service on the whim as a walk-in and I was surprised they were able to take the car and give me a loaner on the spot.

So this is all moot, but I do appreciate the responses. Thanks

Wonder if a reboot would do any good. If it’s actually calling for AC, probably not. And since that is rebooting a dead MCU, even less use, sigh.

Rebooting was the first thing I tried. After multiple tries I did get it to boot up. But the Bluetooth didn’t work (I’d bet there were other features not working, too, but I didn’t try), so I tried rebooting again and it never turned on again.

Have you tried the voice command to see if it still works? "Turn of air conditioning"

Voice commands weren’t working, unfortunately.
 
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And which one is that?
Depending on the car. I assume the MCU dying is an older car, so probably the first one (this is from this wiki thread):

  • Remove fuse 51 for classic cars By wipers, need to remove cover in frunk
  • If not found above remove fuse F235 Next to kick panel on right side, need to remove door sill plate.
 
hello, I am having the exact same issues as you had.. didn't used the vehicle for 3 days and now the mcu is dead and the ac won't turn off. I made an appointment with Tesla but it is in 10 days! this is a model x mcu 1.0