SW17LS

Its adjustable in the user configurable settings. Just keep reducing the sensitivity until you're happy with the length of time it spends on fresh air.

I believe also the system can be set to not default to recirculation when started in any mode. As it is now when you get in the car and its hot and its blowing full force it will switch to recirculation. The reason for that is its quicker and easier to just cycle the cabin air through and cool it down. Mine however goes back to normal outside air once the HVAC cycles down and the cabin gets to a comfortable temp...then auto recirc works as normal.

It takes MUCH longer to cool the cabin initially when not in recirc though.

SW17LS

Here is the page from the manual.

If you are unhappy with how often the system sits in recirculation, you want "efficient ventilation mode" OFF (defaults to on) and you want to adjust the smog sensor sensitivity down.

tompass

Many thanks!!

SW17LS

No problem. You know me, I'm never any help to anybody LOL.

williakz

Please review this thread wrt Efficient Ventilation Mode on ES350 models. There is apparently a mismatch between what is in manual, what actually exists, and the documentation surrounding both.

Note also that 2013 GS450h manual (p.814) shows ONLY two AC settings (both RTI customizable): Auto AC on/off and Smog Sensitivity. There is NO Efficient Ventilation Mode setting. Similarly with 2013 LS460/L (p.880) same two as GS450h and a third setting that disables Eco mode from crippling AC functions (limits compressor & fan operation). I don't have RX, GX, or IS manuals to compare.

Finally note that both 2013 GS450h and LS460/L manuals are explicit in stating (pp. 377,408 respectively) that, when outside temp is above 75F, system MAY (read "will") switch to recirc in order to increase fuel efficiency. Also, system DEFAULTS to recirc on startup - period.

It is possible, though doubtful, that the 2013 GS350 has been given a user-configurable exemption from the restrictive modes forced on GS450h, LS460, and ES350 (and other model?) owners. I remain skeptical...

SW17LS

All I know is how my GS350 has been adjusted, and how it operates. According to what you all are saying you want the system to do...mine does that.

Note that mine is set to efficient ventilation mode ON still. I want it to run recirc when I start it hot. But with my smog sensitivity turned down once it cools down it runs on outside air until it senses smog,

100% satisfied with the operation of my unit.

As for the ES thread above, that discussion seems to be about the ES300h. I would absolutely believe the hybrid has differences in the system based on my previous experience with Toyota hybrids.

williakz

For my 2013 LS460, there just MAY BE an Efficient Ventilation Mode setting that is dealer-settable. (I'll fire up Carista and see later on).

Below is a Lexus LS460 setting configuration worksheet that describes the setting (#13) and its function - not really about AC air intake mode at all. Note that, as with the ES thread complaint, this setting is NOT user configurable as indicated in the manual for the 2013 LS460 under Climate Setting in Vehicle Customization - AS THE SETTING DOESN'T EXIST anywhere in the customization screens.

Note also the 2013 LS460 dealer-only setting #29 which can be used to disable automatic control of air intake mode. Perhaps this is the setting those experiencing problems should change (if it exists!). One could presumably put AC in recirc on initial startup, then switch to fresh air for remainder of trip. Might work...

Regarding the 2013 GS350, do you guys have user-settable AC settings that, in fact, control the air intake mode (recirc/fresh air) of the AC system such that it overrides the "default" mode of recirc only for 75F+ outside temp and recirc always on startup?

SW17LS

It's a dealer only setting, I will double check.

tompass

So I can not find "efficient ventilation" setting mode. Likely because it can only be set by dealer on '13 GS350?

jkeller

I just spent the last 20 minutes playing with the climate system in my 2014. No mater what temp I set, from min-max, it stayed on recirc. I changed smog settings from min-max too, no change. The only time it went to fresh air was when I turned off the ac button manually. As soon as I reclicked the ac button back to on it went straight back to recirc. Even when I set the temp to max and the system blew hot air and seat heater can on it stayed on recirc. Outside temp 85 for information. Engaging s-flow or 3 zone had no effect either. It's sounding like a factory programming decision on Lexus part to me. I'm hoping when I go in fro my 6mth service it can be changed.

SW17LS

Its a dealer setting

williakz

Carista's description of AC settings was as inscrutable as Lexus's various treatments (manual, worksheet, actual). I'll ask Mr. C what's what and report back.

On a different (possibly tangentially related) issue. I fired up my LS in the garage and "outside" temp read 75F which is reasonable (my garage is partially AC'd). I pulled out into the driveway where ACTUAL temp was 91F (known by my big temp dial hung on the outside of garage). It took 35 MINUTES for the LS to ramp up its "outside temp" display from 75F to 91F (delta T of 16 degrees). Why on earth would Lexus insert such a HUGE lag time between actual and indicated outside temp? Surely, the outside temp SENSOR immediately (and continuously) reported 91F when I pulled out of the cool garage into the hot driveway. What possible reason would Lexus have to delay the TRUE reported temp for 35 minutes? I can see ignoring a "blip" for a minute or two, but 35 minutes? What's up with that?

SW17LS

Mine doesn't take 35 minutes, but it does take a while. My guess as to the reason is so that the system doesn't react too quickly to changes in temp the car may encounter while driving. I.e going from concrete to asphalt, entering and leaving a tunnel, etc. I'm not certain if outside temperature plays a role in how the HVAC system regulates the internal temp...

williakz

But why WOULDN'T you want a fast reaction to changing outside temperatures? I suppose it depends on the temp ranges involved. For example, from 75F to 91F, there is NO possible difference in system response (no one has AC set point at 75F+), so why not post instantaneous outside temps? Similarly, in cold temps, who cares whether actual outside temp is "smoothed"? I can envision only a limited range of temps from say 65F to 75F where SOME degree of smoothing MAY be indicated to keep HVAC from going full heat to full cool every minute. But 35 minutes to tell me how *#@$ HOT it is outside? That's just bad engineering.

SW17LS

In terms of a readout you would want a fast reaction time, in terms of providing a steady, even temperature in the cabin you might want to be certain that a change in outside temp is truly a trend moreso than just a temporary environmental shift.

You might care if in cold temps you drove through a tunnel where outside temps rose 25 degrees and your heat cut out.

Again, I don't know this to be the case...its just a guess. I'll check on my Jeep and see if it reacts more quickly. I would say by the time I'm out of the garage down the road, and out on the main road mine has caught up to the actual outside temp. Definitely not 35 minutes...perhaps 5?