Have any of you noticed a big fluctuation in the interior temp of your GS? I can set mine on 76* and it will be okay and then it will freeze us out!!! I have a LS and it doesn't fluctuate. I'm constantly changing the temp setting from 74* to 79* to try and maintain the same interior temperature. Any ideas of what to check? I'm scared to go to the dealership. It's a 6 1/2 hr drive.....

Thanks, Gary

 

I have the same experience too, I usually set the temp at 75 and after about 10minutes of driving the car would get really cold like a freezer.

I don't think there is really anything wrong or to fix about this but to just turn off AC and just run the fan for a few minutes then turn AC back on. I mean hey, too powerfull of an air conditioning system is always better than an underpowered one right?

 

The LS400 has a bigger interior, and bigger interiors do better with even cooling/heating.

Suggest you direct the vent away from your face/hands, etc. It won't feel as cold that way and will feel more even.

 

My GS is only a week old, but I have noticed the same thing. My Acura also has automatic climate control, and it acts the same way but it's more sensitive. I can push the Acura up or down one degree and feel the difference, whereas with the GS I seem to have to nudge it several degrees to cause a change.

I dunno... I always chalked this up to my internal body thermostat variation, not anything wrong with the car!

 

Okay, where is the device that monitors the internal temperature. Maybe I can whack it a few times!!!

I don't mind it getting so cold, it just seems to fluctuate without me changing the setting.

C'mon, please tell me so I can whack something....???

 

Just in front of you on the left (and right) side of the windshield air (defrost) duct is a little "****" called a solar radiation sensor. On the earlier cars the input from these had little effect on the overall outlet airflow temperature. It seems to me that with the advent of dual climate control capability that these sensor have more "say" in how the cliamte control operates. Going from bright sunshine to shade, for instance, might cause a pretty radical change in the airflow outlet temperature.

You can cover (whack!)"yours" (both?) with a thick pad and see if the deviant airflow temperatures settle down.

 

Unless I am mistaken, there are TWO sensors for the HVAC system. One is where wwest mentioned (up on the dash - the dark **** on the left-hand side). The other looks like a mini vent and is located lower on the dash. Maybe around your right knee.

 

There are TWO solar radiation sensors, one on each side near the bottom of the windshield. The sensor by your right knee is an "aspirated" (actively pulls airflow from within the cabin) interior air temperature sensor. IMMHO the solar sensors are most likely the cause of wide (short term) variations in the system's OUTLET air temperature. There can be long term variations but those will be mostly due to widely disparate dual mode temperature settings.

 

Where is the sensor that monitors the outdoor temp. ?

 

Outside Air Temperature sensor

Behind the front bumper but in front of the A/C condensor and radiator. The bad thing about its location is that it is often affected by the radiant heat (while stopped or moving slowly) from these two HOT devices. I relocated mine to the right front fender well.

 

I understand that the GS 1st Gen, has the same system.

But it works to perfection

yezzzzzzzzzzzzzz

 

no problems with mine. mine works great!

 

The interior temp. sensor is about 6'' below the ignition key cylinder. If you look down, you'll see a small square vent approx. 1x1 that sensor measuring the inside temp, if it's not 74 degree or whatever your setting is. The A/C with run cooler untlil that sensor measuring your setting temp.
The sensor in front of the condensor is for the outside temp. It will read a little higher than your thermometer because it's mount close to the heat source.
The sensors on the dash are the Solar Sensors and mainly use for the Auto headlight to measuring the sun light. There one more sensor for the headlight behind the rearveiw mirror.
Your A/C is working fine.

 

If you have DUAL climate control, one setpoint for the passenger and one for the driver, it doesn't matter if you are actually using DUAL mode or not, there is a DIRECTIONAL solar radiation sensor dedicated to each of you. If the sun is shining brightly from the passenger's side then the system outlet airflow from that side will be significantly cooler than your (shaded) side. If you happen to then drive under a cloud then the airflow from the passenger side (in this case) will fairly quickly get less cool.

If you happen to be using dual mode, with differing setpoints, then only GOD (and Lexus) knows what equation is used to determine the disparate outlet air temperature. What I can tell you is that the IAT sensor will be "looking" for the average of the two settings so the cabin's temperature, overall, will eventually settle at this average.

 

i dont have that

my temperature usually set for 72 summer/winter time

when its summer i turn a/c
when its winter it gives me heat

i can ride all day long i dont get freeze out to death