Climate control system questions
 

So after 6 months I still am not clear on exactly how it works. When it's on "auto" and econ mode, it often goes into recirc mode, even when it is cooler outside then in. This happened several times in the winter also when the heater was on. This would make sense if it was also turning the AC on, but it isn't. In fact, the AC seems to not be linked to the auto climate control at all, but must always be turned on and off manually.

So my questions are;

1. Should the AC come on automatically when the inside temp is high? Econ vs. non-econ does not seem to matter.

2. why does it use recirc mode inappropriately? Is this a glitch? Or does my TCH need service?

Thanks in advance.

Re: Climate control system questions
 

AC comes on automatically sometimes, particularly in winter I'm aware of, for things like humidity. I don't usually have my climate control running so I notice it somewhat less. But winter at least, it'll come on to dehumidify (reducing fog/frost).

Recirc is, as far as I'm concerned, badly programmed. As I've whined in other threads, I can see no conceivable benefit to automatically turning on the recirc when it's baking inside the car and the fan isn't even on, much less AC. Only thing it does then is lock the air in more, instead of helping air it out. This is why I recently had my dealer change the air inlet setting to "manual" instead of "auto". If I actually _want_ it on, I'm happy to do that myself, but as it comes on _much_ more frequently when it doesn't make any sense, and I don't always notice it for a while, I'm not interested in turning it back off when it shouldn't be on in the first place.

Others seem happy with the auto recirc, and I'd have no problem with it if it behaved with any sense, but you might want to consider having the setting changed. You may want to print out the configurable settings file to show them exactly what you're talking about (they don't always know what you're talking about without explicit documentation like that).

Re: Climate control system questions
 

I agree 100% with this. I was not happy with the way the auto recirc worked, so I had mine changed to manual recirc the day after I bought the car almost 2 years ago (thanks to info found on this forum!), and I remain very happy with the change.

Re: Climate control system questions
 

Thanks, good to know it's configurable.

I've never had my AC come on automatically. Another weird thing, if I press Auto again (after it's lit) then my AC starts and the AC light comes on.

I should mention I live in Denver with very low humidity.

Re: Climate control system questions
 

I have noticed that the AC on my camry has seemed to turn on or off automatically. It happens when I touch the button on the steering wheel unintentionally. This usually happens only when I am maneuvering the vehicle, rarely while driving in a straight lane.

I think the recirc mode is controlled mostly by the humidity. But that's just a guess.

Re: Climate control system questions
 

Wow, good timing on this thread, for some reason I just noticed this (recirc coming on automatically) last night for the first time. Playing around with it today, it seemed to me like it was using the external temperature as the cutoff for turning on recirc with AC off. As soon as I moved the temperature below the external temp, recirc would turn on.

I also noticed that as I moved the temperature higher, the outlet mode changed - turning on the feet outlets as well as the console outlets. I thought maybe I'd done something the last time I pulled out my Nav unit!

Re: Climate control system questions
 

I am far from an expert on this, but I doubt (but I could be wrong) there is a humidity sensor in the system. I believe there are some pre-determined conditions that lead to recirc "on". There is, however, a sunlight sensor (top of dash). With the climate control in auto mode, on a bright sunny day, I have turned down the fan speed simply by placing a magazine over this sunsor. Removing it ups the fan speed again. It takes a mimute or two to react, so it doesn't keep changing as you go under a bridge or trees. (not many shade trees in Tucson! Hehe)

Maybe someone with a service manual will post what determines the use of auto recirc.

Re: Climate control system questions
 

Check out post #17 in this thread: https://www.greenhybrid.com/discuss/...56/index2.html

Re: Climate control system questions
 

jbollt — I think you're right. I can't find any humidity sensor in the A/C wiring diagram. I'm attaching the system description from the Manual.

Stan