tstead

I live in North Ohio. It is cold. I noticed that since around October, the ventillation has not switched to recirculate when I drive behind a truck pumping out exhaust fumes. It used to do that when it was warm outside, but since it got cold it has not. Yes, I have the vent system in auto as well as the fan speed.

I took the car to the dealer and the service manager said that it was his understanding that the system should switch over. He took it for a test drive and sat behind some school busses and the system did not swap. He said he tried 3 loaner ES350s and got the same response. He said that he could not explain why the system was not swapping. He did conjecture that since all 4 of the cars (mine and the three loaners) acted the same that the system may be operating "correctly." He thought that perhaps the cold had something to do with the operation but could not explain further.

My thought is that since none of the cars swapped, could this be an example of a defect instead of normal cold weather operation? Has anyone else experienced this? They did replace the smog sensor but that has not had any noticeable effect (the car still doesn't swap). have the smog sensor set to maximum sensitivity (all the way to the right).

Any thoughts on this would be greatly appreciated.

Tim

wanderer99

Do you have it the recirculate\fresh air option set to "Auto"? I find when I have that set to "Auto" it will cycle to recirculate\fresh air depending on the outside smog levels. This isn't the full 'Auto' mode for the AC system, just the "Auto" move for the recirc function. Sorry if this sounds confusing...

tstead

I have BOTH the fan control in auto (the button on the left) and the ventillation control (the button on the right).

One strange thing about the ventillation button. When I had my car in the shop (PP+NAV) the loaner ES350 (no NAV) stayed in auto after I turned the car off and back on again. My car always requiers switching after I get into the car and start it back up. I think it starts out in fresh air mode even if I had it in auto prior to turning the car off. The loaner I had remained even after I turned the car off. Why do these two cars behave differently in that respect?

sarge43

I had a question early on about the system staying in recirc and having to be manually moved to fresh air each time I got in the car. I usually keep it in manual mode w/o the a/c with fresh air and then manually select the fan speed or keep it at the lowest fan speed). The dealer said the selection of the recirc/non was made by the system based on the tempurature setting that was selected, regardless of the system being in auto or manual mode. Despite this, I could not get it to start in fresh air (this was in the summer).

Since then (fall and winter) the system will definitely start up in fresh or recirc depending on the temp setting (I rarely have the system in auto mode). All seems to be working fine and is dependent on the temp setting. Hope this helps.

Maybe the outside temp impacts the sensitivity of the smog sensor and you may need to increase the sensitivity to copensate.

NoiseFree

Wanna swap cars?
I have the opposite problem. No matter what I set it to, it switches over to 'fresh air' mode.

This is interesting. I will eventually get to the bottom of this. Today Lexus head office and my dealer couldn't do anything for me, didn't have any answers.

wanderer99

I only have the recirc 'Auto' option set. The left most "Auto" button I do not have selected at all. I have always had the AC on (since day 1), and have the fan speed usually set to the lowest setting. With this setup my car always does the switch from fresh to recirc air when it needs to. Always. It's quite fun watching it at times change constantly. I always get fresh air when possible this way, and the interior still smells like a new car after 20,000kms.

In my case, the recirc cycling on\off to fresh air has nothing at all to do with temperature. I've seen it many times driving down the highway where it will go to recirc behind a vehicle, then switch to fresh air about 5 seconds after I get into a lane with no vehicles in front of me. If there is no one on the highway it will stay on fresh air. If there are lots of cars it will cycle on\off as required. No temperature dependency here. It's great how it always lets me have fresh air wherever possible. This is one part of the car that really works well. I'm not worried about how it starts, and its always in recirc 'Auto' mode so it always works out what to do.

Is this the type of behaviour you are looking for?

vladbph

I have exact same problem.When temperature is 41F and higher it does the swap. If it is 39F and lower it never does. Ironocaly I never seen temperature showing 40F...???!!! But I guess it is another issue.

autiger71

You can set the smog sensor sensitivity setting, When the fresh/recirc button is set to auto, it will cycle to keep noxious odors (e.g., diesel pickups) from gagging you. If you hold the fresh/recirc button for a few seconds with the climate system on, it will bring up the menu you seem to be describing. It must be re-selected to auto after the ignition is powered down, each time.

I got this from another post on this subject. I don't know how to quote from another thread.

YotaCarFan

You can access the smog sensor sensitivity settings screen by holding down the fresh/recirc button for several seconds. However, it only works if the vehicle is completely stopped. Hit the fresh/recirc button to exit the settings screen (again, car must be stopped for this to work). The setting *will* be retained after the car is turned off and restarted in the future.

Note that the smog sensor does not detect particulates. It detects gasses: CO, HC, & NOx.

This vehicle switches between fresh & recirc when in auto mode based not only on smog, but also on inside & outside temperatures and on how bright the sun is on the left and right side of the dash. Since fuzzy logic is used, the switching of modes may seem erratic.

OAKPLANK

Lately, if both AUTO buttons are selected, the A/C light comes on and stays on. My temperature is set at 21c (approx. 70f) with 3C (approx. 37f.)outside.
The air being circulated is just comfortable, not too warm or too cool.
Can someone explain (none nav model)???
oakplank