AC Always Auto Fogging

[Chris Pitt]

Hi Everyone. Looking for feedback if possible. My car is set to Auto Climate at med speed and at 21 degrees Celsius which I has been for around two years of ownership. Last month the AC started giving me issue. After 3 minutes the Auto Fogging comes up and directs flow to screen. I cannot control the spread of the vents when this happens ( and I should not be able to when flow is directed to screen) and the Auto Fogging stays on the whole journey. The journey can take ten minutes to an hour in which periods I have no control when on auto climate. When I go to manual operation the Auto Fogging goes off and I can control the flow on the screen. All loaner cars I have had set to Auto Climate either come on Auto Defogging for about 5 minutes and then go off back to spreading the flow on three buttons, floor, middle and screen.Has anyone had similar issues. The humidity sensor has been changed already but Tesla saying if the car thinks there is humidity in the car then it will go to Auto Defogging. Generally the Auto Defogging is on only to clear screen and not for an hour Or for the whole journey I’ve had car two years and it’s only last month started staying on. Any suggestions welcome. If I randomly press the AC button on and off a few times and then return to auto climate it does sometimes stay on auto without defogging. The car does not have any damp or wet carpets. I just recently heard from another UK chap that he had same issue and managed to have it fixed.

Any suggestions , comments or questions apprecaited

Chris

 

[Gtech]

I had this issue for whole winter. Tesla did a thermal test but everything was fine. They said: send us a timestamp of begin and end ride and let us check the logs. Now last few days was very dry weather so no auto defog... My latest theory is that B pillar cameras where a little foggy maybe the car tries to cure the issue with auto fog but not sure. (Maybe you can verify?)

Ranger is coming Friday for another issue and I will ask him what are the preconditions for auto fog to turn on. Hopefully he can look that up in some database.

 

[Chris Pitt]

I had this issue for whole winter. Tesla did a thermal test but everything was fine. They said: send us a timestamp of begin and end ride and let us check the logs. Now last few days was very dry weather so no auto defog... My latest theory is that B pillar cameras where a little foggy maybe the car tries to cure the issue with auto fog but not sure. (Maybe you can verify?)

Ranger is coming Friday for another issue and I will ask him what are the preconditions for auto fog to turn on. Hopefully he can look that up in some database.

Thanks and will certainly view the other cameras. I’ve never noticed that before. One thing my car didn’t have a fault with so far.

 

[Traguar]

My car has been in the shop for over a week with this issue. Three new humidity sensors were tried, each reading 100% humid. Eventually gota message today that they have never seen this issue before and it looks to be something in the firmware. My car is being returned to me while Engineering department tries to find a fix that will be sent OTA at some point in the future.

 

[Chris Pitt]

Thanks interesting that Tesla replied this is new to them. I have had couple replies from UK Tesla Facebook with same issues that I am seeing. See below reply from Tesla Email just last week. This issue is certainly not new and it’s certainly showing up in certain cars. I was originally told that a batch of humidity sensors that were manufactured were calibrated incorrectly and that is why Tesla were installing and still seeing the issue. Now I get the below. As they say, the backside doesn’t know what the elbow is doing

Hi Chris,


Having reviewed this for you, at present there are no more actionable steps that the service team can take for you. We are currently waiting on a software update being released for this concern, however we do not have a release date for it as of yet.


Best regards


Tesla Service

 

[Gtech]

Thanks and will certainly view the other cameras. I’ve never noticed that before. One thing my car didn’t have a fault with so far.

I asked the Ranger and he said he hears it a lot from M3 drivers but has no solution for it, he said he personally thinks it's a software bug but has also no clue when it will be fixed. I ask him what are the data parameters to turn on auto fog but he couldn't tell me that.

In my car it's not all the time but mostly in the morning and cold moisty weather. Sometimes after driving like 5 minutes auto fog turns on to freeze my toes to death. Sometimes I can overrule it by turning auto on and off but not always.

 

[Chris Pitt]

I asked the Ranger and he said he hears it a lot from M3 drivers but has no solution for it, he said he personally thinks it's a software bug but has also no clue when it will be fixed. I ask him what are the data parameters to turn on auto fog but he couldn't tell me that.

In my car it's not all the time but mostly in the morning and cold moisty weather. Sometimes after driving like 5 minutes auto fog turns on to freeze my toes to death. Sometimes I can overrule it by turning auto on and off but not always.

Same for me. I purchased thermal work socks now which gives me belt and braces fix . I run on manual mode with all three areas turned on by switching auto climate off. Hopefully update will be the solution to this annoying issue. My one unfortunately turns on after three minutes and will stay on the whole journey duration. Appreciate the feedback.

 

[emailrob]

I have exactly the same issue as described. I have a service appt scheduled, and they asked for timestamps (which I gave). They said if they can't replicate it they can't do anything - which is crazy.

I saw someone said Tesla replaced the cabin filters and its been better - so may try that as well. I guess that could cause some issues?

This is what happens with mine:

1. Car climate control is pre-conditioned to around 72F
2. Car is set to Auto when we get in
3. Outside temperatures have been around 80F. Southern California humidity (medium I guess)
4. Me / me+ other half get in the car
5. Around 3-5 minutes auto defogging comes on
6. This diverts all cold air to the windshield, and makes the driver and passenger hot (even though on the windshield, I assume its is not blowing forwards it is not felt cool).
7. The air hitting the windshield doesn't seem as cold as normal, but I have to test that again which is hard if I'm driving. It does not seem that cold when I put my hand towards it, but can't test fully.
8. The only way to stop it auto-defogging is to turn off climate and switch it to manual, pump the fans manually back up to 8 or 10.
9. It doesn't appear to turn off for quite a while (I've not tested it past 10 minutes, as it gets very hot). Certainly I've driven for 10 minutes and it stayed on Auto Defog, which was enough for me to know something is broken.

 

[Chris Pitt]

I have exactly the same issue as described. I have a service appt scheduled, and they asked for timestamps (which I gave). They said if they can't replicate it they can't do anything - which is crazy.

I saw someone said Tesla replaced the cabin filters and its been better - so may try that as well. I guess that could cause some issues?

This is what happens with mine:

1. Car climate control is pre-conditioned to around 72F
2. Car is set to Auto when we get in
3. Outside temperatures have been around 80F. Southern California humidity (medium I guess)
4. Me / me+ other half get in the car
5. Around 3-5 minutes auto defogging comes on
6. This diverts all cold air to the windshield, and makes the driver and passenger hot (even though on the windshield, I assume its is not blowing forwards it is not felt cool).
7. The air hitting the windshield doesn't seem as cold as normal, but I have to test that again which is hard if I'm driving. It does not seem that cold when I put my hand towards it, but can't test fully.
8. The only way to stop it auto-defogging is to turn off climate and switch it to manual, pump the fans manually back up to 8 or 10.
9. It doesn't appear to turn off for quite a while (I've not tested it past 10 minutes, as it gets very hot). Certainly I've driven for 10 minutes and it stayed on Auto Defog, which was enough for me to know something is broken.

My one is still the same. Tesla said wait for a firmware update. I’m still waiting.

 

[Jaselee]

Hi, just recently got a used m3 and I’m noticing this issue. Has anyone been able to figure out a solution for it?

 

[Candleflame]

Hi Everyone. Looking for feedback if possible. My car is set to Auto Climate at med speed and at 21 degrees Celsius which I has been for around two years of ownership. Last month the AC started giving me issue. After 3 minutes the Auto Fogging comes up and directs flow to screen. I cannot control the spread of the vents when this happens ( and I should not be able to when flow is directed to screen) and the Auto Fogging stays on the whole journey. The journey can take ten minutes to an hour in which periods I have no control when on auto climate. When I go to manual operation the Auto Fogging goes off and I can control the flow on the screen. All loaner cars I have had set to Auto Climate either come on Auto Defogging for about 5 minutes and then go off back to spreading the flow on three buttons, floor, middle and screen.Has anyone had similar issues. The humidity sensor has been changed already but Tesla saying if the car thinks there is humidity in the car then it will go to Auto Defogging. Generally the Auto Defogging is on only to clear screen and not for an hour Or for the whole journey I’ve had car two years and it’s only last month started staying on. Any suggestions welcome. If I randomly press the AC button on and off a few times and then return to auto climate it does sometimes stay on auto without defogging. The car does not have any damp or wet carpets. I just recently heard from another UK chap that he had same issue and managed to have it fixed.

Any suggestions , comments or questions apprecaited

Chris

your car sleeps does it? i.e. at night?

 

[Chris Pitt]

your car sleeps does it? i.e. at night?

Update is that the issue was still present as of two weeks ago. Car was due in for suspension issues and I asked the service department to revisit my Auto Defogging, which they did. The car was there for four days to which three were spent testing and monitoring the Auto Defogging. Time stamps also showed Auto Fogging was staying on much longer than it should be. Initially they suspected humidity sensor, then possible wiring issue and onto possible bad connection to the humidity sensor. I asked for them to change cabin filters also. Filters were 2 years old and not much issue with them But changed anyway. Service changed the humidity sensor and I had the car returned to monitor. They did advise that there might be firmware issue but asked I monitor it and keep time stamps. My issue was as everyone describes and is not common to be doing no matter. Should come on when required for around 5 minutes and go back to standard. My one was on after 5 minutes and staying on most if not all my journeys, 10 minutes to 40 minutes. First day back and Auto Defogging operated as I picked car up from centre, went of five minutes after and the last two days with 40 minutes journeys has had only 1 Auto defogging come on mid journey for 5 minutes. So far looks ok for me. I did also over year ago have a faulty Louvre that had snapped. This was changed and I wondered if any vents were not working correctly. Mentioned that to the service so they may have found something else they repaired without mentioning on report. So, new cabin filters replaced along with new humidity sensor and confirmation connection to the sensor was tight.

Does car sleep at night? Drive it home, plug it in and let it do its thing. I’m not a person to be checking app all time, so yes car is shut down until I unplug in the morning if it’s been on charge. Hope that makes sense and good luck to everyone with same issue. Was a nightmare and very frustrating issue.

 

[lovelybai]

Just came back from service, no solution found. They tested it on another “good” car and had the same issue. so they marked mine as solved and ready to pick up.