A very good A/C tutorial for RX 350 dated Sept. 2020........

 

Did they do away with SFlow?

 

Looks that way unless the "DUAL" button is doing that job now, so confusing!

 

According to the 2021 RX User Manual, S-FLOW is still there. @raylor4, have a look at the manual and look for the S-FLOW settings. It will show you how to turn off S-FLOW, so the rear vents will still blow air when your wife is driving alone.

There was another thread on here about how to permanently turn off S-FLOW, but I'm not sure if anyone has successfully done that. On my 2018, if I open any of the rear doors before starting the car, the rear air vents always blow air even if I'm alone; but that trick might not work on every model year.

 

Usually if there is no one detected in the rear seat the rear air vents are off.

 

Definitely confusing. Ray A.

 

kolokmee - Thank you for mentioning the S-flow feature. I found it in the owner's manual. I've switched the flow to the rear vent manually and it seems to be working he way we want now. Thanks everyone for your help. Ray A.

 

FYI the rear vents turn off in eco mode regardless of someone sitting there or not.

 

Really! That's absurd. I will definitely need to test this the next time we have rear seat passengers. I cannot imagine what they were thinking when they came up with this design. Thanks for sharing that detail.

 

Thanks for the tip. We drive in normal mode all the time. Ray A.

 

We have eco (drive and AC) mode all the time on the 2017 model, and the rear air vents blow air. Eco mode just does not run the compressor as much or as fan as high as in normal mode. From the manual:
■ Operation of the air conditioning system in Eco drive mode
● In the Eco drive mode, the air conditioning system is controlled as follows to prioritize fuel efficiency
• Engine speed and compressor operation controlled to restrict heating/cooling capacity
• Fan speed restricted when automatic mode isselected
● To improve air conditioning performance, perform the following operations
• Adjust the fan speed
• Turn off Eco drive mode

 

After all this reading I still can't figure out how to disable S-Flow in my 2021 RX350 Luxury package. I disable it in the settings but it defaults back the next time I start the car. I would like front and back vents to thrown air all the time. I have 2 zones, not 3. Frustrating. Thanks.

 

A few of the earlier posts above mention that S-Flow can be permanently disabled at the dealer via techstream.

So your best bet would be to get your dealer to make that customization the next time you bring the car in for service.

 

Thank you. I will do that.

 

I was able to disable S-Flow on my 2020 RX350 w. Luxury package with Carista ($29.99 from Amazon + I went for the 1 year fee to unlock all its features). Carista is simply great, you can make all of the "dealer" customizations yourself