Auto de-fogging

[Leejmoff]

It'll force the climate control on after a while as well.

I was cruising on heated seats only and found that it'll start up the climate control by itself and then put it in defogging mode even when there's no fog.

My guess is they can read cabin humidity directly and have to infer it based on temperature readings. It does seem to get it wrong a lot of the time.

this is what the service centre told me. If they sensors believe its too humid, the auto defogging will come on. But, this never happened last winter in the same car. Some settings have changed and its rubbish.

We need an option to turn off auto defogging.

 

[Obie]

Last winter defogging only when needed, this winter it's been every drive and mostly not needed.
After reading this thread and getting annoyed at the hot head cold legs auto climate i booked a Service Appointment to get it checked out.
Just did a 45 minute drive after booking in and of course no defogging for first time this winter, go figure

 

[MrBadger]

When auto fogging is on, are people noticing the rear seat vents blowing out a lot of hot air? I put my hand over rear vent after rear seat passenger complained and what was coming out was pretty hot.

All on auto but low fan speed. Wonder if that relatively new option explains some of the differences since last year.

 

[hgmichna]

We need an option to turn off auto defogging.

I would prefer automatically, but better. I am generally for automatic operation wherever possible. The fewer options, the better.

But, of course, if good automatic operation could not be done for one reason or another, then we would need a manual option.

 

[Planky]

Is anyone still having this issue after the latest software update 2023.44.1?

 

[ACarneiro]

Is anyone still having this issue after the latest software update 2023.44.1?

Yep, haven't noticed any change....

 

[Leejmoff]

yep no change, still rubbish and turning on randomly

 

[markbmcfc]

Is anyone still having this issue after the latest software update 2023.44.1?

I may be mistaken but i'm pretty sure this only became annoying in 2023.44.1 for me.

I don't remember it being an issue until the latest update.

 

[WllXM]

I'm wondering if this is linked to B pillar cameras being blinded in the morning....

 

[Planky]

I may be mistaken but i'm pretty sure this only became annoying in 2023.44.1 for me.

I don't remember it being an issue until the latest update.

I’m on 2023.38.6 and it is constantly degfogging it in my M3

 

[Plagued]

I'd suggest people put through a report. If everyone is saying the same thing they should act. Can you still do a voice command in the car with "bug report"? that's probably the best way of reporting as they'll get sensor info.
So if you say "bug report", followed by something like "unable to turn off front demister and not needed" when it's happening they should get some useful data.
Alternatively you can just put a service request in and let them close it after acknowledging.

 

[MrT3]

I may be mistaken but i'm pretty sure this only became annoying in 2023.44.1 for me.

I don't remember it being an issue until the latest update.

I'm still on 2023.32.9 and it's an issue for me. I think it did start with 2023.32, although that may just have coincided with the weather getting colder.

 

[MrBadger]

I'd suggest people put through a report. If everyone is saying the same thing they should act. Can you still do a voice command in the car with "bug report"? that's probably the best way of reporting as they'll get sensor info.

Bug report does not apparently report bugs!

Tesla told me that a bug report simply added a relatively short lived (10d/2w ish) marker into the logs that pointed Tesla in the time frame of the issue.

However, Tesla needed to be notified separately to the bug reports otherwise they would be lost after a short period of time.

No additional report within the time frame, and even then they may take time, if ever, to view, otherwise no more a bug report than a gratifying placebo.

 

[Obie]

Now the weather has warmed up a bit its stopped defogging all the time and the AC is on most of the time, when it was colder and non stop defogging the AC was off.
You would think it would run AC when defogging, think its software rather than the sensor.

 

[Jason71]

Now the weather has warmed up a bit its stopped defogging all the time and the AC is on most of the time, when it was colder and non stop defogging the AC was off.
You would think it would run AC when defogging, think its software rather than the sensor.

It may have been too cold for the AC to run. AC systems can be prone to icing in cold weather.
When the air passes over evaporator it cools and this forces moisture in the air to condense into liquid water. Normally this drips away hence the pool of water under a car with an AC system running but in cold weather the system can get so cold that the condensed moisture then freezes turning the evaporator into a solid block of ice. The car would have anti icing sensors and shut the AC down if that happened I would think.
Not to mention AC's primary purpose is to cool the air and it uses energy doing so, and if the air is too cold to requires it the car may shut it off. The down side is that can lead to fogging because AC dries the air as described above so without it running fogging can be much worse.

 

[ACarneiro]

The down side is that can lead to fogging because AC dries the air as described above so without it running fogging can be much worse.

I would disagree slightly on this point.
If air is so cold outside (low single-digits or lower) that it leads to icing on the evaporator coils or shuts the AC down, then its absolute humidity is probably low enough that, once warmed to 20 degrees C or so it'll have a fairly low relative humidity.
"When I were a lad", in times and in a country where car A/C was a rarity, you were still quite capable of defogging the windscreen just by cranking up the heat
I would be more inclined to put my money on yet another not-quite-properly-implemented automatic solution by Tesla. They have precedent

 

[MrT3]

You would think it would run AC when defogging, think its software rather than the sensor.

Yes, but you are making an assumption that the display is accurately representing what is actually happening. It may well be on, and fixed on, it just doesn’t show it. It may also be that the system has a dehumidify mode, similar to a home a/c or heat pump system, and they use that instead?

 

[Obie]

Yes, but you are making an assumption that the display is accurately representing what is actually happening. It may well be on, and fixed on, it just doesn’t show it. It may also be that the system has a dehumidify mode, similar to a home a/c or heat pump system, and they use that instead?

You are quite right, the ac compressor will be running all the time even when not showing on the display. I was thinking of how a traditional ac system works but the Tesla heat pump is way more complicated than that.
Just watched this video that explains it very well but my head still hurts! tesla heatpump how it works - Google Search

 

[LiamPope]

Yeah very annoyed by this this year. Was fine last year. Defogging just stays on blasting hot air in my face and even my kids complain! But turning climate off and back to auto fixes it for me. It wasn't broken - why did they need to fix it??

 

[dcfas]

I switched to manual because the fan is always running at 5 or higher, even when it says low in auto. I dislike the air blowing in my face so always pull the vents lower and deselect the windshield vent.

Every so often in the AM the windshield fogs up and I simply turn on the defrost. Otherwise, manual seems… automatic.