scfz1000

Hi, i noticed the mode setting in the car will switch from floor to floor/vent in auto mode even it it is cold outside....today it was 50 in the morning and after driving awhile the car was nice and warm and then the auto mode moved the air from the floor to the main vents...making you feel cold again...really weird....my old honda accord auto mode would just leave it on floor and lower the fan speed and temperature to keep the current temp setting.....in the summer i;m ok with this behavior in the lexus but in winter it is a pain...is something broken or is this normal.

DunWkg

At least from my experience, you've described what happens. I think once up to the cabin temperature you've set the car enters, what may be described as, circulation/ventilation mode. It's neither heating nor cooling, but adding a bit of outdoor air and circulating a constant temp air, which feels cool due to a kind of wind chill effect.

I think it kind of happens like this: if you have the system set to auto at say 72 degrees and you also have it set to bring in outdoor air and the temperature in the cabin is 68 degrees, the system will heat. Once up to 72 degrees, the system switches to circulating/ventilation mode. In this mode it is circulating 72 degree air around in the cabin while adding just a small percentage of outdoor air. While this air is 72 degrees, it's blowing out the dash vents and feels cooler due to a wind chill effect. It's in sort of a neutral position, neither heating nor cooling. It is circulating and ventilating (bringing in outdoor air).

I usually do one or two things: throttle down the dash vents, raise the temp up a degree or two or I do both.

scfz1000

yes, that is exactly it....too bad it is not adjustable...oh well....