I can find no where in the manuals or documentation that tells me what this switch turns On and OFF on the AC control panel.

In my opinion Lexus has very poor documentation for use of the AC system.

What does this switch do and where is it documented.

 

Turns AC on meaning you're going into manual mode for climate control for quick heat or cool.

 

That switch turns off the rear vents. If no one opens the rear doors before driving, this switch automatically activates.

 

Is that the S-Flow switch? Page 288 in the manual.

 

Yes. That's the technical name for the switch

 

BTW that switch also seems to shut off the passenger-side vents if if there is no one in the seat and the extra cooling is not needed. If a passenger is in the seat those front vents are on. My biggest "challenge" is remembering to turn off the S-Flow switch when people are in the rear seat!

 

It should come on when there is someone in the back seat. It gets activated by opening the rear door.

 

As a double 450h owner, S-Flow has zero advantages for me. I have to over ride it every time I get in the vehicle.

i will ask Lexus if they can override it to stay OFF. When I get in a hot car, I want BOTH center vents pushing cold air.

 

I normally put my briefcase behind the drivers seat, then I climb in. Whenever I have checked the rear vent after driving for a while, the rear vent is not blowing any air. I would expect that on days with temperatures above 85F, all vents would be working to cool the car.

I looked on Carista to turn Sflow off, but it had no setting.

 

I suspect that it is not on because you put the briefcase in before starting the car. I don't know if that's how it works or not. I know that if I pick someone up and they get in the back the air is moving. You can always just hit the s flow button. I find the whole system a little different. I don't like the sflow that much and would prefer it just blows air everywhere all the time. It would be nice to have an on/off button for the air.

 

Today, the kids got on the back, then I got in. The rear vent had no air and the kids complained it was hot. I had to turn off the s-flow and then the rear vent started blowing air.

I am not sure how S-flow detects passengers. The manual states that of a rear door is opened and closed, the S-flow turns off. However, that is not my experience. Maybe the rear door must be opened after the front door.

 

I think Lexus might be changing this in the future and allowing the driver to have the vehicle default to always on. Reason I said so is that I am participating in a Lexus driver survey I get every week. In the second survey there was extensive questions about how often people sit in the back seat and how often you over rode the s-flow button.

I want my S-Flow off all the time. My 450h saves no fuel by using it and when the vehicle is really warm the extra vents are desired to cool the vehicle quickly. They just need to have the S-Flow button to remain at the last driver setting.

 

I agree ! It's absolutely infuriating and saves nothing

 

Strange, I can turn off my s-flow and it stays off.

 

If I open one of my back doors to toss something in the back seat and then get in the car it always turns off S-Flow and illuminates the rear seat belt light on the dash.