Climate Control Temp.

[05silverls430]

I'm used to cars with automatic temperature controls giving you the ability to "set it and forget it". In my past 3 cars (2 Audis and 1 Acura) that have had this feature, I have set the digital thermostat to about 72 degrees, and have always been comfortable, no matter what the season.

With my new ('03) LS430, I'm constantly having to adjust the temperature, anywhere between 70 and 74 degrees. I've had the vents blowing cold air when the temp. is set to 72, even when it's cold outside. If I put it up 2 degrees to 74, the air gets warm instead. Often times too warm. And then when it's warmer outside, 74 won't cut it, so I'll turn it down to 72 and the fan will come on much too high, blowing cold air with too much force.

What I'm getting at is that the temperature is hard to adjust. I haven't been able to find a degree setting that I can set and leave it on. I nkow that I can manually control the fan speed, but the point of the Auto setting is that you should be able to set a certain temperature, and the car should be able to maintain it automatically (hopefully with some consistency).

Does anyone else have this problem? I also experienced cold air blowing out of the left center vent and hot air out of the right (at the same time) on one occassion. I thought that was sort of strange. I know that these cars have various sensors (solar sensors?), and can sense whether someone is sitting in the front seat (or maybe any seat for that matter) and directs the air accordingly.

When I took it into the dealer for service, I had them check the climate control system out, and of course "everything is functioning normally".

I was just wondering if this is something that is inherent to Lexus or to the LS, and something that I should just get used to. Or should I pressure the dealer to figure out what's going on and fix it?

[wwest]

I'm used to cars with automatic temperature controls giving you the ability to "set it and forget it". In my past 3 cars (2 Audis and 1 Acura) that have had this feature, I have set the digital thermostat to about 72 degrees, and have always been comfortable, no matter what the season.

With my new ('03) LS430, I'm constantly having to adjust the temperature, anywhere between 70 and 74 degrees. I've had the vents blowing cold air when the temp. is set to 72, even when it's cold outside. If I put it up 2 degrees to 74, the air gets warm instead. Often times too warm. And then when it's warmer outside, 74 won't cut it, so I'll turn it down to 72 and the fan will come on much too high, blowing cold air with too much force.

What I'm getting at is that the temperature is hard to adjust. I haven't been able to find a degree setting that I can set and leave it on. I nkow that I can manually control the fan speed, but the point of the Auto setting is that you should be able to set a certain temperature, and the car should be able to maintain it automatically (hopefully with some consistency).

Does anyone else have this problem? I also experienced cold air blowing out of the left center vent and hot air out of the right (at the same time) on one occassion. I thought that was sort of strange. I know that these cars have various sensors (solar sensors?), and can sense whether someone is sitting in the front seat (or maybe any seat for that matter) and directs the air accordingly.

When I took it into the dealer for service, I had them check the climate control system out, and of course "everything is functioning normally".

I was just wondering if this is something that is inherent to Lexus or to the LS, and something that I should just get used to. Or should I pressure the dealer to figure out what's going on and fix it?

It's simple, really.....

During the times when you, your human body, feels "cool", "coolish", be very diligent about keeping the system airflow only to the footwell. Then you will be able to maintain a human comfort level at a constant setting. In automatic mode the system will often switch to "cooling" mode, airflow to your face and upper body, even when your body is saying, Sheesch, it's kinda cool in here.

If its any comfort to you I actually sued Lexus over this issue as a result of purchasing my very first Lexus, a new 1992 LS400. I lost.

There is an aspect of human body comfort of which Lexus, Toyota, and especially NipponDenso (Denso US) seem totally unaware. The human body comfort equation has more than one parameter, three, as a matter of fact., at least only three primary ones.

There is the air temperature surrounding our bodies.

Radiant heating from direct sunlight.

And lastly, but FAR from the least important of these, radiant heat recieved by our bodies from the "surrounding" "landscape".

Put yourself in a room wherein the air temperature is somewhat elevated ABOVE your normal comfort level, but with the surrounding walls and ceiling CHILLED, and you will not, cannot, be comfortable. The chilled surrounding walls will make you feel coolish, if not downright COLD.

Your Lexus automatic climate control, on the COLDEST night in the dead of winter, will automatically switch into COOLING mode, primary outlet airflow to the face and upper body, once the cabin temperature has been raised to your air temperature setpoint, or closely thereto.

You can help yourself somewhat by having the dealer make a change to two of the more "secret" C-BEST settings. These would prevent the A/C from running automatically absent your own manually intervention.

But the method whereby you will help yourself the most is to manually over-ride the system into footwell outlet airflow if, when, the dominant radiant temperatures of the surrounding "landscape", components inside the car and out, are sending a reasonable levl of radiant heat "to" your body.

[SKperformance]

I have another take on the problem.

I made a post awhile ago about the interior cabin temp sensor.

It has a vacuum that sucks air past it from the ventilation system.

Over time it gets dust and dirt build up causing the sensor to be inaccurate.

It basically needs to be cleaned as the dust causes the sensor to not see the actual temp of the cabin air as the dust is an insulator. Only when the dust heats up enough to transfer the heat will the fan speed decrease .

If you look to your dash beside your right knee you will see a small 1 inch opening that has a few slots. It is where the air is being injected for the sensor.

There are 2 ways to clean it

the proper way is to remove the panel and sensor and wipe it clean with a q-tip.

The second is to take compressed air and blow it into the opening with the heater on full fan and recirculation. You could see the debris come out the vents.

let us know how it works out as i had similar problems over time on both my Lexus'. As soon as i had done this to my LS i noticed that the fan and temp of the air would increase almost instantly when i open a door and the cold air comes rushing in and cooling the sensor.

[05silverls430]

Thank you both, wwest and SKperformance. I'll try the compressed air method on the vacuum sensor, and also be prepared to override the automatic controls, if necessary. Interesting that you sued Lexus, wwest. I guess I'm just used to the automatic systems in Audis and Acuras, neither of which needed constant adjustment....

Oh well... Thanks again!

[wwest]

Thank you both, wwest and SKperformance. I'll try the compressed air method on the vacuum sensor, and also be prepared to override the automatic controls, if necessary. Interesting that you sued Lexus, wwest. I guess I'm just used to the automatic systems in Audis and Acuras, neither of which needed constant adjustment....

Oh well... Thanks again!

Hot left, cool right....

Your car has two sunlight radiant heating level sensors, detectors, one on the far right at the bottom of the windshield, and another for the driver, on the far left. If the sun happens to be shining BRIGHTLY on one but not the other the sunshine side might get significant cooler airflow than the opposite side.

".....constant adjustment....."

While I sorta buy into the "dirty" cabin temperature sensor delaying the functionality of the climate control I don't believe that even if true the delay would be such that it would be noticeable, let alone cause the symtoms yours exhibits. The Lexus climate control is fast acting, reacting, for radical differences between your temperature setpoint and the actual cabin temperature, but the closer the cabin temperature gets to your setpoint the longer the designed in time constants become. To do otherwise would be counter to Lexus "pesonna" and would undoutedly be discomforting.

"...neither of which...."

Acura uses the same climate control vendor as Toyota and I have seen no end of complaints of sudden windshield fogging and just plain "how do I keep the windows from fogging up" questions from owners.

As for Audi (and Porsche) it is my understanding that their (Bosch) biggest problem in this "venue" is that they will quite thoroughly CHILL the windshield on the hottest summer day and that subjects their owners to sudden windshield fogging on the outside surface.

[wwest]

Just went back and reread your post and it appears your complaint more concerns the way the system reacts to NEW temperature setpoints than the way it acts, reacts, on it own once the temperature setpoint is reached.

In automatic mode when you first get into the car and the cabin is coolish, significantly below your setpoint, the outlet airflow will always be from the footwell outlets. That airflow might be fairly warm, even hot, but you will not be so sensitive to that as you might were it coming from the dash vents.

AS the cabin air temperature rises and gets to within ~5-8 degrees of your setpoint the system will switch to footwell/dash combined. Once within 2-3 degrees the primary airflow will be via the dash outlets only.

If the predominant radiant effects to your body are on the coolish side this "cool" and dry airflow will definitely be discomforting.

So you move the setpoint up a few degrees, say 72F to 74F. Since Lexus is so NOISE adverse the most likely system response is to raise the temperature of the system air outflow while leaving the blower on the lower speed it went to back when the cabin first "reached" the setpoint.

AND...

A move from 72F to 74F would often not be enough difference to warrant the system reverting to footwell outlet mode. So now you're setting there being discomforted by uncomfortably warm airflow to your face and upper body.

And remember, even if your changed temperature setpoint is of enough difference to warrant the system switching to footwell mode, once the cabin reaches or approaches the new setpoint you will be back to square one.

Unless you actually need the A/C cooling purposes, not just for dehumidification of the incoming airstream, keep the system out of "cooling" mode by over-riding it into footwell mode. It would also help somewhat if you turn the A/C off entirely, the cooling aspects, the refrigerant compressor.

My 2001 RX300 has a c-best setting that will allow the driver to disable the A/C indefintely simply but manually turning it off one time. You can bet that my C-best settings are such that the A/C NEVER cycles, not even in defrost/defog/demist mode, unless I wish it too.

[CJAsis]

I'm actually very intrigued by this post.

Our 97 LS has auto climate control as does my 98 NSX and our old (now sold) 2000 RX300. In each case, we set the temp. control to 72 and forget about it. Both my wife and I stay comfortable.

We recently bought a 2006 LX470 and I am really frustrated with the climate control. I'll be hot as hell even with the temp. set at 72 and my wife in the passenger seat will be fine. I can feel hot air coming out of the vents on the driver's side but cool air on the passengers side. It's really weird.

I haven't brought it up to the dealer (we've only just now got 1,000 miles on the car) but I will when it goes in for its free 5,000 mile service.

[05silverls430]

I'm actually very intrigued by this post.

Our 97 LS has auto climate control as does my 98 NSX and our old (now sold) 2000 RX300. In each case, we set the temp. control to 72 and forget about it. Both my wife and I stay comfortable.

We recently bought a 2006 LX470 and I am really frustrated with the climate control. I'll be hot as hell even with the temp. set at 72 and my wife in the passenger seat will be fine. I can feel hot air coming out of the vents on the driver's side but cool air on the passengers side. It's really weird.

I haven't brought it up to the dealer (we've only just now got 1,000 miles on the car) but I will when it goes in for its free 5,000 mile service.

It makes me feel better that I'm not the only one experiencing this. Maybe it is normal, but there has to be a reason. I've seen information about the solar sensors that wwest is referring to. I've even seen ads for this feature in car magazines.

Let us know what happens when you take it in and mention it to the dealer.

What dealer do you use, BTW?

[CJAsis]

It makes me feel better that I'm not the only one experiencing this. Maybe it is normal, but there has to be a reason. I've seen information about the solar sensors that wwest is referring to. I've even seen ads for this feature in car magazines.

Let us know what happens when you take it in and mention it to the dealer.

What dealer do you use, BTW?

It's going to be a while before we actually get to 5,000 miles but I will post up our findings.

We have had very good luck with Tustin Lexus for service. However, I'm really looking forward to Newport Beach Lexus opening later this year! It will be far more convenient for us and it looks to be very much along the lines of Fletcher Jones (ie every possible amenity and feature for the owners to enjoy)

[wrpsuite]

so I'm having the same issue warm left cold right vents , diagnostic says #21 Solar sensor, anyone ever replace?

Thanks

[SKperformance]

do a search on the solar sensor ,

[wrpsuite]

I did, that's how I found this old thread, I'm hoping someone has actually replaced one and can tell me how involved itis?

do a search on the solar sensor ,