Question on S-Flow
07-20-19, 05:07 AM
#32
The theory behind the Split Flow feature is that when you are alone in the car it will
direct little or no HVAC to the rear or passenger seats. Weight over approx. 40 lbs
in the passenger seat will enable the SIR (airbag) system and the Airbag ON light
will illuminate which brings on the HVAC to the right vents. The default setting is to
Enable S-Flow when the RX starts, dealer can use a Techtool to change default to OFF.
Are you driving with the Drive Mode in "ECO"? Unlike the "Sport" setting, ECO stays on
after an engine restart and affects the HVAC output considerably.
Do you have the air vent(s) other than the drivers closed down? S-Flow is intended to
restrict the air flow without you having to reach and bend but you or your (apparently rare)
passengers can close them off. If closed you will get more air and air noise to the driver.
Does your parking environment lend itself to leaving the sunroof vented? If you are not going
to get dust or leaves floating in, consider that. The Lexus Remote Start App will show the
status of sunroof open if you are inside and it starts to rain...can not close it remotely however
Another Techtool setting to consider if not already enabled, Remote Window Rolldown lets you
press and hold the key fob "unlock" button long enough to partially or fully open the windows
and sunroof. Vents quite a lot of hot air by the time you get in.
direct little or no HVAC to the rear or passenger seats. Weight over approx. 40 lbs
in the passenger seat will enable the SIR (airbag) system and the Airbag ON light
will illuminate which brings on the HVAC to the right vents. The default setting is to
Enable S-Flow when the RX starts, dealer can use a Techtool to change default to OFF.
Are you driving with the Drive Mode in "ECO"? Unlike the "Sport" setting, ECO stays on
after an engine restart and affects the HVAC output considerably.
Do you have the air vent(s) other than the drivers closed down? S-Flow is intended to
restrict the air flow without you having to reach and bend but you or your (apparently rare)
passengers can close them off. If closed you will get more air and air noise to the driver.
Does your parking environment lend itself to leaving the sunroof vented? If you are not going
to get dust or leaves floating in, consider that. The Lexus Remote Start App will show the
status of sunroof open if you are inside and it starts to rain...can not close it remotely however
Another Techtool setting to consider if not already enabled, Remote Window Rolldown lets you
press and hold the key fob "unlock" button long enough to partially or fully open the windows
and sunroof. Vents quite a lot of hot air by the time you get in.
The fact is the entire volume of air within the cabin needs to be cooled for optimal comfort and when S-Flow is activated ⅔ of the cabin has reduced airflow. This is a "feature" I can't believe Lexus wasted a single $1 developing - the rationale from the start is flawed especially since I can't tell the difference in airflow in the front seat with S-Flow on or off - in other words it doesn't feel any colder or blow any harder when S-Flow is diverting airflow just to the front so now it's just restricting airflow to 2/3 of the car. Brilliant!
I want a job working for a car manufacture where engineers present stupid ideas like this and I just ask why and then smack them in the head.
Last edited by PWMDMD; 07-20-19 at 05:10 AM.
The following users liked this post:
ravenuer (07-20-19)
07-20-19, 02:41 PM
#33
Intermediate
While the S-Flow button is gone on my 2019 the S-Flow is still present. It was beastly hot the other day and I got into the car alone and noticed no air was coming from the rear vents. I picked up the kids and suddenly there was airflow back there - I'm guessing opening the rear door triggered it.
The fact is the entire volume of air within the cabin needs to be cooled for optimal comfort and when S-Flow is activated ⅔ of the cabin has reduced airflow. This is a "feature" I can't believe Lexus wasted a single $1 developing - the rationale from the start is flawed especially since I can't tell the difference in airflow in the front seat with S-Flow on or off - in other words it doesn't feel any colder or blow any harder when S-Flow is diverting airflow just to the front so now it's just restricting airflow to 2/3 of the car. Brilliant!
I want a job working for a car manufacture where engineers present stupid ideas like this and I just ask why and then smack them in the head.
The fact is the entire volume of air within the cabin needs to be cooled for optimal comfort and when S-Flow is activated ⅔ of the cabin has reduced airflow. This is a "feature" I can't believe Lexus wasted a single $1 developing - the rationale from the start is flawed especially since I can't tell the difference in airflow in the front seat with S-Flow on or off - in other words it doesn't feel any colder or blow any harder when S-Flow is diverting airflow just to the front so now it's just restricting airflow to 2/3 of the car. Brilliant!
I want a job working for a car manufacture where engineers present stupid ideas like this and I just ask why and then smack them in the head.
07-22-19, 11:32 AM
#34
It is really inconsistent how the rear door opening controls the s-flow. More than once, with passengers in back seats, the s-flow was still on, and I had to push the button to give them air.
07-22-19, 12:35 PM
#35
It may be that once deactivated the back door opening will allow the flow to take place, but am not certain.
05-05-20, 03:40 PM
#37
Today my Lexus dealership disabled the Auto S-Flow in my '17 RX at no charge.
I tried doing it myself on Carista but it's not an option. I called Carista technical support and they confirmed as much.
I tried doing it myself on Carista but it's not an option. I called Carista technical support and they confirmed as much.
06-05-20, 05:25 AM
#38
2020 F Sport A/C Delay?
Its already 108° heat index in Oklahoma and our RX a/c seems to either have a long delay after starting or after traveling from an idle position. It appears quite a bit longer then any other vehicles we have owned.
Anyone else have the same problem or maybe know why?
Thx
David
Anyone else have the same problem or maybe know why?
Thx
David
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BiggerOkie (06-08-20)
06-08-20, 04:05 AM
#40
TYVM.....I didn't even know about this "feature", if you want to call it that. It might work well in other climates, but for us we want all we can get right from the start. It absolutely worked rx450h, thx again.
06-08-20, 08:19 AM
#42
Intermediate
06-08-20, 09:54 AM
#43
Yes that's what I said, but the S flow is always off UNLESS you press the button and the green light goes off.
I was corrected when I thought that the green light meant the the A/C was on for the rear seats.
I was corrected when I thought that the green light meant the the A/C was on for the rear seats.
07-14-20, 11:02 AM
#44
Pole Position
What Does “S-Flow” Mean?
Why is it called “S-Flow”? And is there an easier way to get A/C or heat to the rear passengers than futzing through the menu screen? Where’s the hard button as in my’17R (I now have a 2020)? Any other “nuances” that make this easier?
Last edited by daryll40; 07-14-20 at 11:09 AM.
07-14-20, 11:33 AM
#45
Lexus Test Driver
Energy saving airflow control. With S-Flow on, doesn't it detect passengers and direct air automatically? My wife has it on her 17RX, we never touch the control and it seems to work properly.
