lesz

I guess I'm confused. With my ES, whenever the outside temperature reads 75 or higher on the dash display, the climate control system goes to recirculate, and, whenever the outside temperature is below 75, it goes to fresh air. Since, in most situations, I want fresh air, I've gotten into the habit, whenever I start the vehicle and it is 75 or above outside, to manually hit the fresh air/recirculate button so that it will switch to fresh air. I wonder if there is some other possible personalized setting that you have that is different from mine, but since there are only 2 personalized settings for the climate control system, that doesn't seem likely. The other possibility that comes to mind is that, mid production run, Lexus might have changed the default setting for fresh air/recirculate and that our the climate control systems of our two vehicles might work differently from each other.

amphipri0n

Even with the AC off, the car will still automatically switch to recirculate when Auto is set for the fan if the outside exhaust/smog sensor triggers it.

Arty101

I could see if the outside temp is 75 or higher, the climate control would go to recirc. It does that with my GS and my older RX, with or without AC on when I set my temp to something as low or lower than the outside temp. But setting a higher inside temp to 75 or higher when the outside air is 70 or lower, going into recirc with the AC on doesn't make sense to me.

Also, I've set the recirc. smog sensor to the lowest sensitivity, thinking that may be the issue. These last few days have been very clear, especially being near the ocean so I don't think that's the problem either.

lesz

When you go into the customizable settings for climate control on your ES, do you have 3 available settings or just 2? In my ES, there are 2. One is for auto AC and the other is for the smog sensor sensitivity. But, in the manual, it shows a 3rd customizable setting called "efficient ventilation mode". From what the manual says, I think that that setting would relate to the behavior of the fresh air/recirculate button. In the default, fresh air or recirculate would be automatic, like in my vehicle, but, if disabled, I think that it would change the fresh air/recirculate function to a completely manual function. But, again, even though that setting is in the manual, it isn't in my vehicle. I wish it were because, if it were, I think that the system would operate the way I would like it to operate. In any case, the presence of the setting in the manual and the absence of it in my vehicle makes me think that there might have been a change made somewhere in the production run and that my vehicle may have been built at some point after the change and after the manuals were written.

(Also, note that there is a dealer only programmable setting called "efficient ventilation mode" listed in the Lexus customizable settings pdf, but the description of what it does is completely different from the description of the "efficient ventilation mode" that is described in the manual and that is supposed to be able to be set by the user but that is not actually in my car.)

Arty101

No, I have the same two custom settings you have - the Auto AC and Smog Sensor. I don't believe there was a change during production from your car and my car with this "feature". I think Lexus had this programmed into their climate system way back in the day. I never liked it on my GS and RX since it changed the recirc and fresh air setting with or without AC depending on the ambient temp and my set temp. I usually leave the AC off and set the temp to 68, but when the outside temp goes above it, then it automatically will start up in recirc when I start up the car. NBD since you can switch it to fresh air, with or without AC since there's a AC dash button.

Perhaps if you have Techstream, you can check out how "Efficient Ventilation Mode" really works. If you don't like it, or wasn't what you were expecting, you can change it back.

lesz

When I have time, I may play around with Techstream and see what happens if I change the efficient ventilation mode in the dealer only settings, but I doubt that it will make a difference because, according to the Lexus customizable settings pdf, that setting changes whether or not the compressor is automatically used when defrosting the windshield, while, again, in the manual, there is a completely different description of the efficient ventilation mode that is supposed to be a user setting and that is supposed to control whether fresh air/recirculate can be controlled completely manually.



I'm wondering if the difference between how your fresh air/recirculate works and how mine works might still have something to do with the smog sensor. It could be that, even when set to the least sensitive setting, if you are driving in an urban area, there still could be enough smog to cause the system to change to recirculate, instead of doing it based on the 75 degree cut off. I live out in the country, and I would imagine that it would be very rare for me to drive anywhere where there was much measurable smog.

In any case, even if I would have designed some things in the climate control system to be different from the way that Lexus did, this whole discussion is an excellent example of a first world problem. I can imagine large numbers of people shaking their heads in disbelief that these issues are of concern to us.