New MX Owner issue- Cabin heats up at night on it's own

[Miamipoker]

I have had my car for about 3 weeks and noticed the battery draining pretty severe at night Like 10% per night.
I installed tessie and it shows my heat is coming on randomly throughout the night and during the day while I'm not driving. The outside temps are around 30 degrees Fahrenheit the inside temp is around 50 degrees but it randomly turns on the heat and pumps it up to 80 degrees. I don't have any automations setup ... Any ideas? it's a 2017 MX

 

[mxnym]

My best guess is a bad occupancy (seat) sensor indicates the driver is present and wakes up the MCU, which controls the heat. If you turn off the heat before you get out, then it probably won't heat if this is the scenario. Another possibility is that your door could be opening and closing. When the door opens, the MCU wakes up, and as previously mentioned, it controls the heat. Once again, if you turn off the heat before exiting the vehicle, then it won't run in this scenario. There was a bug in the firmware years ago (I think actually in late 2017, possibly in 2018) where the door would open as you walked away, but that is long since fixed, so if you door is opening, it is likely being triggered somehow, for instance, a cat playing with the fob or a purse containing the fob.

 

[Miamipoker]

Thanks so much for your reply.. There is another issue that the heat is probably tied to.. The passenger is registering as being open even though it's closed. It's also not pulling closed properly you have be really slam it to close it. Another post .. But the heat could be tied to that. Thanks for your help

 

[mxnym]

Thanks so much for your reply.. There is another issue that the heat is probably tied to.. The passenger is registering as being open even though it's closed. It's also not pulling closed properly you have be really slam it to close it. Another post .. But the heat could be tied to that. Thanks for your help

Yes, when any door opens, the MCU activates, so it sounds like that sensor is malfunctioning and flipping back and forth. Definitely turn your heat off when leaving the vehicle until you get that fixed.

ETA: Also, if you use your alarm, keep in mind that it either A) isn't activating -or- B) could randomly go off in the middle of the night because of this, so you might also want to take preventive action on that front.