AC starts in re-circulation mode

[Borisu]

Something that I noticed but haven't called the dealer about yet: If I shut down the engine with AC on, almost every time (and that almost is what's bugging me the most) I turn it back on, whether in a few hours or the next day, re-circulation air mode is turned on along with AC. I know for a fact that I didn't leave it in that mode as I always use it with outside air intake, so that's something that it does on its own.

I originally blamed it on a faulty temperature selector and thought that it maybe "too close" to Max Air option where re-circulation is turned on whether you like it or not, but I was running it not at the coolest setting yesterday night (with AC on) and when I turned it on this morning, it started in the same re-circ mode, with AC on.

It's not something that requires an extra visit to a shop, assuming that's not a normal behavior, but I'm not a fan of technology having a mind of its own without my approval.

Also, what concerns me is that on couple of occasions it didn't turn the re-circ mode on when I started the engine. I didn't find any pattern with outside temperature at the time either- when I start it in the morning in the garage, it's usually a comfortable 60-70F.. when I start it outside in the PM, it maybe 90F.

 

[The Waco Kid]

Mine does it too... It's annoying because if I forget to change it + Houston humidity eventually leads to my ac smelling like butt.

I keep the Lysol at the ready just for that occasion.

 

[3wbdriver]

Mine does it too. I believe it is programmed that way because the A/C will run more efficiently cooling already cool air from the interior rather than hot outside air.

 

[rigtec]

Something that I noticed but haven't called the dealer about yet: If I shut down the engine with AC on, almost every time (and that almost is what's bugging me the most) I turn it back on, whether in a few hours or the next day, re-circulation air mode is turned on along with AC. I know for a fact that I didn't leave it in that mode as I always use it with outside air intake, so that's something that it does on its own.

I originally blamed it on a faulty temperature selector and thought that it maybe "too close" to Max Air option where re-circulation is turned on whether you like it or not, but I was running it not at the coolest setting yesterday night (with AC on) and when I turned it on this morning, it started in the same re-circ mode, with AC on.

It's not something that requires an extra visit to a shop, assuming that's not a normal behavior, but I'm not a fan of technology having a mind of its own without my approval.

Also, what concerns me is that on couple of occasions it didn't turn the re-circ mode on when I started the engine. I didn't find any pattern with outside temperature at the time either- when I start it in the morning in the garage, it's usually a comfortable 60-70F.. when I start it outside in the PM, it maybe 90F.

Hi Borisu,

The temperature control system Doesn't just look at 'Indoor/Outdoor' temperatures while calculating the target temp setting on the display. It also considers the O.A.Q. (Outdoor air quality) while processing your cooling/heating request. So if Humidity is a factor it will make an 'executive decision' to close the outdoor air damper (Recirculate mode) to avoid introducing an unacceptably high humidity factor, and poor air quality into your environment!

Cheers

 

[Borisu]

I forgot to mention that it's a TE, so no "target" temperature or any sort of automatic climate control.

I guess my "almost every time" indicates some weird glitches, which, unless I can figure out how to duplicate them on demand, I'd have to live with.

It is annoying as I often use it when it's cool outside but I want to dry air out a bit, but if that's "by design", I guess not much I can do about it.

 

[msp]

I forgot to mention that it's a TE, so no "target" temperature or any sort of automatic climate control.

I guess my "almost every time" indicates some weird glitches, which, unless I can figure out how to duplicate them on demand, I'd have to live with.

It is annoying as I often use it when it's cool outside but I want to dry air out a bit, but if that's "by design", I guess not much I can do about it.

x2...same behavior and model..

 

[rigtec]

I forgot to mention that it's a TE, so no "target" temperature or any sort of automatic climate control.

I guess my "almost every time" indicates some weird glitches, which, unless I can figure out how to duplicate them on demand, I'd have to live with.

It is annoying as I often use it when it's cool outside but I want to dry air out a bit, but if that's "by design", I guess not much I can do about it.

Okay, in the case of Non-Automatic Climate Control systems... if you have the air discharge registers set to any position other than: 'Windshield or Windshield/foot' positions, the system will Default to the Recirculate mode. That may be the cause,

Rgds!

 

[alexb]

Same here on my TE. It used to drive me crazy but now I mostly just ignore it. What [MENTION=83083]rigtec[/MENTION] said about the humidity makes sense makes sense. It seems in the cooler/drier months it would not switch to recirc as often, but now with this muggy humid summer it stays on recirc pretty much constantly.

 

[alexb]

Okay, in the case of Non-Automatic Climate Control systems... if you have the air discharge registers set to any position other than: 'Windshield or Windshield/foot' positions, the system will Default to the Recirculate mode. That may be the cause,

Rgds!

Interesting. On previous cars they all recommended to not run in recirc mode for extended periods of time and that it was not good for the system. On my Infiniti it would automatically turn it off after a while.

 

[FlyNavy]

I forgot to mention that it's a TE, so no "target" temperature or any sort of automatic climate control.

I guess my "almost every time" indicates some weird glitches, which, unless I can figure out how to duplicate them on demand, I'd have to live with.

It is annoying as I often use it when it's cool outside but I want to dry air out a bit, but if that's "by design", I guess not much I can do about it.

Not insulting anyone's intelligence here, but might the rotary switch be hard over (Past the barely noticeable detent) into the Max Cold position? That will cause it to go to recirc every time it's turned on.

 

[philsey]

One would think the owner's manual would explain this? But, I've been wrong before.

 

[The Waco Kid]

One would think the owner's manual would explain this? But, I've been wrong before.

It's there. I remember it vaguely, but I can't be bothered to find it or post it up as it really is a "first world" problem.

 

[Antman]

Okay, in the case of Non-Automatic Climate Control systems... if you have the air discharge registers set to any position other than: 'Windshield or Windshield/foot' positions, the system will Default to the Recirculate mode. That may be the cause,

Rgds!

Mine doesn't do that.

The only time mine EVER goes into Recirc mode is when I select Max A/C, or if I physically select the Recirc button. Doesn't matter if it's 110 degrees 100% humidity.

In fact, in any mode other than Max A/C, if I have Recirc selected, it will only stay on Recirc for a few minutes before switching back to normal.

If I press and hold the Recirc button for a few seconds, it will stay on Recirc until the truck is turned off, or until I press the button again- whichever comes first.

Mine is a 2011 SR5...

 

[rigtec]

Interesting. On previous cars they all recommended to not run in recirc mode for extended periods of time and that it was not good for the system. On my Infiniti it would automatically turn it off after a while.

Hi alexb,

In an A/C system, there's a temperature range (50-90 deg) that the system is designed to work within... if the ambient temp is Too High, the system can't operate or cool properly, due to the excessive heat. If the surrounding temperature is Too Cool, there's a real danger that the Evaporator coil will freeze-up; preventing the refrigerant from boiling when it should, and so returns to the compressor as a liquid (instead of a gas), potentially causing the pistons/valves to break apart.

There weren't as many technical advances in micro-processing back in the 80's and 90's, so I think the reasoning of the automobile engineers was to prevent the coil from freezing caused by an operating environment with a dangerously low heat load.

Cheers!

 

[Hawaiian4runner]

Mine doesn't do that.

The only time mine EVER goes into Recirc mode is when I select Max A/C, or if I physically select the Recirc button. Doesn't matter if it's 110 degrees 100% humidity.

In fact, in any mode other than Max A/C, if I have Recirc selected, it will only stay on Recirc for a few minutes before switching back to normal.

If I press and hold the Recirc button for a few seconds, it will stay on Recirc until the truck is turned off, or until I press the button again- whichever comes first.

Mine is a 2011 SR5...

2010 Trail. Mines works exactly as you described. Here in Hawaii, humidity is close to 100% all the time.

 

[Bevo]

Mine doesn't do that.

The only time mine EVER goes into Recirc mode is when I select Max A/C, or if I physically select the Recirc button. Doesn't matter if it's 110 degrees 100% humidity.

In fact, in any mode other than Max A/C, if I have Recirc selected, it will only stay on Recirc for a few minutes before switching back to normal.

If I press and hold the Recirc button for a few seconds, it will stay on Recirc until the truck is turned off, or until I press the button again- whichever comes first.

Mine is a 2011 SR5...

Exactly how mine works as well.

 

[rigtec]

Mine doesn't do that.

The only time mine EVER goes into Recirc mode is when I select Max A/C, or if I physically select the Recirc button. Doesn't matter if it's 110 degrees 100% humidity.

In fact, in any mode other than Max A/C, if I have Recirc selected, it will only stay on Recirc for a few minutes before switching back to normal.

If I press and hold the Recirc button for a few seconds, it will stay on Recirc until the truck is turned off, or until I press the button again- whichever comes first.

Mine is a 2011 SR5...

Hi Antman,

I don't dispute your experience with your own truck (you're quite qualified as a tech), but I knew that I had read that somewhere in my 2012 Toyota manual, and so I looked and found that pg (315), "See below in the Blue trace":



I'm not very familiar w/ non-automatic climate controlled systems, but it does say that.

Rgds!

 

[Antman]

Hi Antman,

I don't dispute your experience with your own truck (you're quite qualified as a tech), but I knew that I had read that somewhere in my 2012 Toyota manual, and so I looked and found that pg (315), "See below in the Blue trace":



I'm not very familiar w/ non-automatic climate controlled systems, but it does say that.

Rgds!

It does say that. It also says that is in "Max A/C" mode. Max A/C is the only switch position that will allow this to happen, in other words.

 

[FrontRange4Runner]

Not insulting anyone's intelligence here, but might the rotary switch be hard over (Past the barely noticeable detent) into the Max Cold position? That will cause it to go to recirc every time it's turned on.

I was going to say the same thing. My guess is that a lot of people have the dial turned all the way to the left. This is "Max AC" and uses recirc mode because it is more effective at cooling the air. Turning the dial one click to the right will keep it out of recirc unless you press the button.

 

[Borisu]

Okay, in the case of Non-Automatic Climate Control systems... if you have the air discharge registers set to any position other than: 'Windshield or Windshield/foot' positions, the system will Default to the Recirculate mode. That may be the cause,

Rgds!

According to the manual that's how the system is supposed to work in "Max A/C" mode