Someone please explain the "auto" climate control

[Crypty]

The thing most perplexing to me is the hot/cold knob between the center vents which seems to work when in auto mode. Doesn't this negate the automaticness of being able to set a temperature and let the car sort out the rest? How does this all work, or more importantly how was it intended to be used?

[jphughan]

From what I can tell reading the manual and experimenting, Auto only seems to regulate whether the AC is on or just the fans, which vents the air is directed to, and sort of controls fan speed. You can still control fan speed with Auto on, but that seems to be RELATIVE fan speed in Auto mode, because for example when I get into my car after it's been sitting out in the sun, the fans blast on to try to cool down the interior fast and then slow down after a few minutes even though I didn't change the fan controls.

And as you say, in Auto mode the center knob still works. However, (and there are already several threads about that knob, but I'll indulge you anyway), that knob only controls the temperature of the air that comes out of the two center vents, not the entire car. This is designed so that if you're in a cold climate, you can turn on the heater to warm up your interior but still blow cold air on your face to keep you from getting drowsy due to it being warm and toasty in your car. Some people don't bother with it, others apparently can't live without it. I personally keep it all the way on cold since there are very few parts of the year in Central Texas where I'm using the heater rather than AC.

[jmgM3]

After almost a year of ownership this is still one of the most puzzling things about my M. It just seems rather redundant... to me anyways.

[Ghetto2315]

Apparently, the Blue/Red knob in-between the vents is not for Cold/Hot.

The Blue side is to let ouside air in, while the Red side is inside air and only works for the front vents only. Not feet or windhield vents.

The example I was given was in the winter time, if you have the heat on your feet or windhshield, keep the knob on blue and it'll take air from the outside and blow through the front vents.

Not be to be confused with the re-circulate button

[mdosu]

http://www.m3post.com/forums/showthread.php?t=547298

[mdosu]

Originally Posted by Ghetto2315

Apparently, the Blue/Red knob in-between the vents is not for Cold/Hot.

The Blue side is to let ouside air in, while the Red side is inside air and only works for the front vents only. Not feet or windhield vents.

The example I was given was in the winter time, if you have the heat on your feet or windhshield, keep the knob on blue and it'll take air from the outside and blow through the front vents.

Not be to be confused with the re-circulate button

nope, knob is for face vents temps only. In winter time, I put the knob on middle setting or on cold but still turn up the heat with the climate control knobs.

[jphughan]

Originally Posted by Ghetto2315

Apparently, the Blue/Red knob in-between the vents is not for Cold/Hot.

The Blue side is to let ouside air in, while the Red side is inside air and only works for the front vents only. Not feet or windhield vents.

The example I was given was in the winter time, if you have the heat on your feet or windhshield, keep the knob on blue and it'll take air from the outside and blow through the front vents.

Not be to be confused with the re-circulate button

I'm pretty sure this is wrong, otherwise how would that be any different from the recirculate button? That would mean there are two ways to manage recirculation for the front vents and only one way for everything else?

I'm pretty sure that the winter driving scenario you observed wasn't because it was letting outside air in. Rather, it was doing exactly what I described above, namely heating the rest of the cabin but blowing cool air through the front vents since you had it on the Cold side.

[Ghetto2315]

Originally Posted by jphughan

I'm pretty sure this is wrong, otherwise how would that be any different from the recirculate button? That would mean there are two ways to manage recirculation for the front vents and only one way for everything else?

I'm pretty sure that the winter driving scenario you observed wasn't because it was letting outside air in. Rather, it was doing exactly what I described above, namely heating the rest of the cabin but blowing cool air through the front vents since you had it on the Cold side.

I've talked to a few of my colleagues and that is what they told me. I just leave mine on the Blue regardless lol. Maybe I'll shoot corporate an email seeing if they can get me a 100% correct answer

[s4play]

hey guys, odd question but my entire climate control system is DEAD - won't power up all of a sudden!

Is there a fuse for the climate control? I didn't do anything and it just died....or is this something I have to take to dealer?

[jimf15e]

I only say this because its not an intuitive design, but did you inadvertently turn it off by lowering the fan speed? I think if you do, the only way to power it back on is to push the fan speed increase button. Just a shot in the dark.

[s4play]

^thanks but I hit every button on that damn display.....haha

Is there a fuse on this circuit?

[sg///M3]

Is the AC always supposed to come on when set in "Auto" mode?

[ChrisK]

Originally Posted by sg///M3

Is the AC always supposed to come on when set in "Auto" mode?

Don't forget that AC is not only for cooling, but used as a dehumidifier.

[Obioban]

Wrote this for the e46, but most of it applies to the e9X as well...

Originally Posted by Obioban

Since it seems like everyone in the world tries to use it a manual climate control, which it's terrible at, instead of automatic, which it's wonderful at, I thought I'd write a little guide :roll:

1) Choose the temperature you want the inside of the car to be. For most people this will fall somewhere between 67º and 72º. Personally, I'm most comfortable at 69º. The answer is NOT in the 50s or 90s (would you set your house thermostat to 91º? No, that would be ridiculous).

2) Set the temp display to your chosen 67-72º temperature.

3) Press "auto"

4) SET THE RED/BLUE DIAL TO THE WHITE LINE. AKA, it's purpose it not to be set to red in the summer and blue in the winter.

5) Press the recirc button until the left light is illuminated. That is the automatic position.

6) Done. Never touch it again, the car will take care of everything.




To clear up some misconceptions that seemingly everyone has:

1) setting the temp into the 50s will NOT make the car cooler any faster in the summer than leaving it on, say, 68º auto. The car will run the compressor and fan on full to achieve the target temp.

2) Similarly, setting the temp to 90º will not make the car get warm any faster in the winter. The car will crank the heat as soon as the heater core is generating enough heat for it to be beneficial to do so

3) The red/blue/white dial. 98% of the time, the correct position is the middle (white line) position. If you think the e46's climate control sucks (it doesn't), it's probably because you've messed with that dial. The purpose of the dial is to control the temp of the air blowing on your face beyond the climate control program. Good examples of when it can BRIEFLY be useful to tweak it: You just left the gym and you're overheated-- set to blue till comfortable, then back to white. Or, you just went trekking through the snow for days and need hot air directly on your hands and face-- set to red till comfortable, then back to white.

The default behavior of the dial is to blow cool air on your face while keeping the car at a comfortable (your chosen) temperature. Cool air is statistically proven to keep you more alert when driving, which is why this is done. On particularly cold mornings it will automatically blow warm out there till the cabin is warmed up, so there is no need to tweak it for that.

4) DO NOT TURN OFF THE AC COMPRESSOR. In the winter. In the rain. In the summer. In the fall. In the spring. In the winter, the AC compressor acts as a dehumidifier. Ever wonder why your windows fog up an other people's don't? It's because you turned off the AC compressor so your cabin is full of humidity. Same thing in the rain. It continually blows my mind how many people I see driving around in the snow/rain with their windows cracked and car fogged up, trying their hardest to see and not knowing that they are the cause of their own problems. Oh, and the AC compressor automatically disengages when your floor it, so it's not going to cost you any acceleration, either. Also, the AC compressor gets lubed through use, so not using it for long lengths of time will lead to premature failure. And, the car is less fuel efficient above 40 mph with the windows down and ac off than it is with the windows up and AC on, so you're not saving any gas, either.

5) The recirculate button. Three settings-- recirc, auto recirc, and no recirc. Auto recirc detect man made smells (chemicals, exhaust) and will automatically put the car in recirculate mode. 99% of the time, that's the mode my car is in. The exception is that it can't detect biological smells (e.g. rotting dead animal, skunks, etc). If you're going to be stuck next to one for a while, probably behooves you to put it on recirc for the duration.

6) unless you have specific reason to do so, don't direct where the air is flowing (as in, leave the lights on feet/face/dehumid on the left turned off). The car will move air about automatically as required.



So, to recap-- choose your temp, press auto, recirc in auto, snow flake on, dial to white, and stop touching it.

Used properly, the e46's climate control is pretty excellent. It can keep you comfortable year round without you ever having to touch it. In fact, the ONLY downside I can think of is there's no one touch off button.

Used manually, or trying to out smart it, it's a terrible system that constantly needs tweaking.

Originally Posted by Obioban

And if you'd like to learn more about e46 climate control and how it works, this is a fun read:
http://www.bmwcarx.com/web/Documento...lClimatico.pdf

It's actually a pretty amazing system. Might make you stop trying to out smart it :roll:

[Bubbles]

Originally Posted by Obioban

Wrote this for the e46, but most of it applies to the e9X as well...

Nicely done.

[davesaddiction]

Originally Posted by Obioban

4) SET THE RED/BLUE DIAL TO THE WHITE LINE. AKA, it's purpose it not to be set to red in the summer and blue in the winter.

Thank you.

I was wondering why it was always so cold when I had the heater on...

[LarThaL]

The climate control on the M3 is really discombobulated IMO. A climate control needs 3 dials: vent setting, temperature, fan speed. It then needs a recirc function, and a dehumidify function. That's it.

[davesaddiction]

Originally Posted by LarThaL

The climate control on the M3 is really discombobulated IMO. A climate control needs 3 dials: vent setting, temperature, fan speed. It then needs a recirc function, and a dehumidify function. That's it.

Typical German over-engineering...

Needs mehr buttons!!!

[dreamspeed]

My personal experience is that following the lengthy instructions above does not work to MY liking, YMMV

A BIG part of how hot or cold i feel is directly related to the temperature of air shooting at me directly from the center vents. The foot vents and top vents might help regulate the temperature but personally i think they are pretty useless. To me the only point of the top vents is to defrost.

I'd be perfectly ok with having ONLY center vents (besides the whole defrost thing).

That being said if you leave the center blue/red dial in the middle it actually just creates a crappy middle of the road situation where it's this nasty lukewarm air shooting at my face.

Having it in the middle means it won't be cool enough when the temperature is hot and it won't be hot enough when the temperature is cool.

And it seems like BMW climate control have a heavy top/foot vent bias when you set it on AUTO. Meaning out of a 100% total power it will do something like 25% power center, 35% foot, and 40% top.

Therefore i just leave the temperature dial at 72, put it in manual mode with only the center vent activated, and then increase or decrease the fan strength manually when needed. I also just move the center red/blue dial left or right when necessary.


Maybe this system works for some people but for me it's just a hassle...

[Z K]

I've found the Honda auto climate controls pretty confusing as well. There's Full Auto and just Auto and you can change settings and still have Auto or Auto Off. All you get is 1 Auto button to do all this crap though.

In the M3, I leave the auto off and just turn the temp knobs, fan level and manually set AC on and off.

[weaksauce]

The red blue dial is one of my fav features of the car esp in winter. When I first get in the car, many times I want the front vents to warm hands and face. After few mins of driving, I get sick of warm air on face and want the vents to blow colder air but the entire car to continue to warm.