Climate Control Issue

[Stang70Fastback]

Originally Posted by B-R-Z

Why does the AC always come on with auto mode? Normally it's only for defogger and actual cold air conditioning. Kind of annoying.

It's also annoying when people ask a question that was asked in the very first post and answered in the second, lol.

[B-R-Z]

Ok what you just said is annoying too. I read the subject and this page of posts and didn't see it. Relax chief.

And I don't agree with your explanation either, I'm not saying you're wrong or right, I just think it's bad design if that's how it is. It shouldn't default it to on, unless there is a sensor in the car that can detect humidity. Every other car that I owned required you to turn on defogger if your windows fogged. Makes sense.

[Stang70Fastback]

Well I would be willing to bet that it's very possible the A/C isn't running the entire time. It may very well only run when it senses high humidity. Lots of Japanese vehicles operate this way.

For example, when you turn on the rear window defogger, every 15 minutes it will turn off for two minutes, but the light will remain on. Perhaps the A/C light illuminates because the car is saying, "hey I might use the A/C every so often to bring cabin humidity down," but that doesn't mean it's necessarily always running.

I think the only way to get a definitive response on the connection between the physical light and the status of the A/C compressor is either someone with way too much time on their hands, or tracking down a technician who knows the logic of the system (which means not your local dealership tech, unfortunately.)

I wonder if SoA would be bothered to get me the proper answer if I email them...

[ntron1]

The person you want to ask is from Toyota and works in Detroit.

[Foobar]

Mine comes on with auto but turns off eventually so there must be some kind of humidity sensor somewhere, or its just timed.

Also, there's no performance loss since the compressor shuts off when you accelerate to give you more power.

Sent from my Nexus 5 using Tapatalk

[Stang70Fastback]

It only shuts off at like WOT though, right?

[B-R-Z]

Originally Posted by brz880

The dealer can change that setting with the techstream tool

I don't think its a techstream setting. Have you confirmed this?

[brz880]

Yes, I have disabled it on mine

[B-R-Z]

Where can I find the setting? I have techstream & cable

[iLaw]

As stated before, the A/C comes on to de-humidify the air, preventing window fogging. It also reduces that grimy film that builds up on windows (if they aren't cleaned regularly)

I have noticed that the A/C in Full Auto automatically turns off (or doesn't activate in the first place) if the temperature is -1 C or lower... I can only assume that when the air is that cold, the air isn't humid (because the water molecules in the air would freeze).
We had a few days (in the Greater Toronto Area) where the temperature hovered around -3 to +3 C. My A/C always deactivated at -1 C or colder.

As a personal preference, I manually turn off the A/C in Auto mode if its warm enough to drive with the windows down. I let the HVAC system do whatever "Auto" does when my windows are up.

[brz880]

It's hidden under customize / air conditioning / compressor mode / auto or manual

[B-R-Z]

Originally Posted by brz880

It's hidden under customize / air conditioning / compressor mode / auto or manual

Awesome, thanks, this solves that issue

[m3bassman]

Originally Posted by Bobblehead

The reason the A/C comes on when you press auto is because while its warming the car, its also dehumidifying the air. It does that to keep the inside comfortable, but mainly to keep your windows from fogging up.

well said.

most people do not understand that the A/C is the compressor running that is pulling water from the airstream. they falsly assume A/C means cold air. In my toyota, when i flip to defrost setting, you can hear the A/C compressor switch on but it blows hot.

[B-R-Z]

Again ... It's not always humid in the car yet the compressor always comes on when Auto is pressed.