Welcome to Tesla Motors Club
Discuss Tesla's Model S, Model 3, Model X, Model Y, Cybertruck, Roadster and More.
Register

Auto and Remote Climate Control Bug - Floor Vent Hurricane

This site may earn commission on affiliate links.
tl;dr: No matter the conditions, climate control starts at full speed on floor vents when started in auto mode or when started remotely from app.


Excessive details:
For the past two weeks (since July 18) I have had a consistent issue with my HVAC in auto mode and with remote pre-conditioning. Whenever the car starts with air conditioning in auto, or whenever climate control is started remotely, it swaps to floor vents with the fan at full speed. It's obnoxiously loud from the outside of the car, and when you get in there's a foot-tornado occurring.

I first noticed this also affected remote climate control the next day, when 20 minutes after I started preconditioning, the interior temp had only dropped a few degrees when I opened the app. As I was heading out I could hear the HVAC system in turbo mode from about 30-40 yards. When it's really hot outside, the air just can't get very cold at those fans speeds, so it's really ineffective at cooling.

I’ve tried several scroll wheel reboots, driver profile changes, different HVAC configurations, etc. but have had no success with anything. I reported to Tesla (ServiceHelpNA) on July 23, and they forwarded it to my service center, but I have not heard back from the service center.

While I'm in the car, I can fix it temporarily by changing climate control to manual mode, activating the forward vents and turning off floor vents, and then put it back in auto. From this point it works fine in auto and remains on the forward facing vents as long as the car remains on. But once the car shuts down, HVAC starts back up on floor vents the next time the car is started or when remote climate control is engaged.

I also ran a test in my garage by letting the cabin get down to the set temperature and then shutting the car down. When the car restarted, HVAC still went to floor vents at full speed despite the interior temp matching the set temp. I've seen it eventually get down to 66 degrees in the car when the temperature was set to 74 after the sun went down.

I can get around the auto mode issue by just staying in manual, but this doesn't fix the remote climate control issue. Apparently when you activate it from the app, it uses auto mode despite how it was set when you left it. Once you get there and open the door, it switches back to manual and to the forward vents and last fan speed. So I've stopped preconditioning entirely in order to avoid passersby thinking a Tesla is about to catastrophically explode. Plus it's just not very effective as noted above.

The only thing I know of that may have contributed to this is I had performed a few resets on July 18 (at the request of service) to attempt to address an issue with my passenger side signature LED strip being out. I think I also created a new driver profile that day. I was and still am on 21.9, so I'm not sure if a firmware update will reset it to normal.

I've searched far and wide and cannot find this issue documented anywhere. Has anyone else experienced anything like this?
 
Got this fixed today. For anyone that comes here from the future with the same problem, you will have a solution. After I got my headlight replaced a couple weeks ago, we also talked about this issue, and the next day my mobile service tech and engineer were able to remotely determine that the temperature and humidity sensor (THS) was not communicating. He came back this morning and fixed it within a few minutes.

The THS is up in the rear-view mirror housing. As soon as he disassembled it he could see that it was disconnected. Easy fix. I had my windshield replaced in early June, so the assumption is that the connector wasn't fully inserted after the windshield install, and over time it vibrated loose. Everything is in order now. Firmware updates had also been failing due to this issue, but he pushed 28.5 and it installed successfully. It's good to have a properly working HVAC system again.
 
I have a similar issue, but I did not have any work done on my windshield. i did have the car in for service to replace the power conversion system. Upon completion of that, the service center loaded the latest firmware 16.2. The AC worked fine on my long trip back home (auto mode and AC came out the top vent as it should). However, the next day and all subsequent starts, the air only comes out the bottom vent in auto mode as you described. Also, the "Keep Climate Control On" option is grayed out and non functional in park and by remote app even though my battery charge is > 25%. I have tried reboots, etc., with no luck. I contacted the service center and am waiting to hear back. My assumption is that my issue is firmware related rather than the humidity sensor since the "Keep Climate Control On" feature is grayed out. Hopefully, reprovisioning of the firmware will fix it.
 
My floor vent hurricane problem has re-surfaced. Working perfectly for nine months after initial repair, the windshield was baking in the hot Florida sun this morning. I’m guessing that a faulty connector affected by high heat is to blame. Service scheduled.

Manual AC control sucks, makes me appreciate even more how incredibly well Auto settings worked.

Perhaps completed unrelated: HomeLink also stopped working at the same time.

I still bet on a sensor/connector issue.