MCU Failure and AC stuck on

[Droschke]

Unlikely that you have mobile access, but if you do, you can turn off the AC from your app

Disconnecting/reconnecting the 12V might shut the AC down for now, when the car is not being charged.

 

[Alysashley79]

I don’t recommend letting the AC run for 10 days because then you’ll end up paying for mcu and condenser unit. $$$. Have you tried doing the two finger salute? (Assume so)
Tesla built in the “on” for air if the mcu fails so if it’s hot or cold you won’t be either sweating or freezing.
If the two finger salute doesn’t work I’d recommend just taking it to tesla and having them disconnect the 12v and letting it sit until they can fix the mcu or replace it.

 

[Droschke]

Disconnecting/reconnecting the 12V might shut the AC down for now, when the car is not being charged.

just taking it to tesla and having them disconnect the 12v

I think if he can disconnect/reconnect the 12V himself (or have someone to do it for him) while the car is not connected to the charge cable, the AC will not come back ON.

 

[sgray496863]

Just an update here. I found some suggestions to pull the touchscreen fuse from the fuse box and then re-insert it. I did that as it is way easier to gain access to than the 12v. That actually seemed to reset the system and turn the AC off. When I turned the car on the AC started back up but when I locked it the AC shut off as it would normally do. Still no touch screen functionality but at least the AC won’t be running non stop. Hopefully can get it to the SC tomorrow if they are open (doubtful) but at least by Tuesday to get this MCU upgraded. Thanks

 

[Alysashley79]

I think if he can disconnect/reconnect the 12V himself (or have someone to do it for him) while the car is not connected to the charge cable, the AC will not come back ON.

It actually will if he gets into the car in the drivers seat for any reason because it’s the mcu1 fail safe so that it can be driven. Safely and comfortably.

 

[Droschke]

Just an update here. I found some suggestions to pull the touchscreen fuse from the fuse box and then re-insert it. I did that as it is way easier to gain access to than the 12v. That actually seemed to reset the system and turn the AC off. When I turned the car on the AC started back up but when I locked it the AC shut off as it would normally do. Still no touch screen functionality but at least the AC won’t be running non stop. Hopefully can get it to the SC tomorrow if they are open (doubtful) but at least by Tuesday to get this MCU upgraded. Thanks

The touchscreen fuse reset was going to be my next suggestion, but I could not remember the exact location of it. Glad you figured it out. If you can afford the MCU upgrade go for it. Fixing the eMMC is just a band-aid.

 

[Droschke]

Just an update here. I found some suggestions to pull the touchscreen fuse from the fuse box and then re-insert it. I did that as it is way easier to gain access to than the 12v. That actually seemed to reset the system and turn the AC off. When I turned the car on the AC started back up but when I locked it the AC shut off as it would normally do. Still no touch screen functionality but at least the AC won’t be running non stop. Hopefully can get it to the SC tomorrow if they are open (doubtful) but at least by Tuesday to get this MCU upgraded. Thanks

Was it fuse #51 (20A)?

 

[sgray496863]

Was it fuse #51 (20A)?

Yes that was the one. The 12v is just a pain to get to in my model. Thanks for all the help!

 

[gaswalla]

Thanks for the follow up OP. Best of luck w the service center