Automatic HVAC controls - how to disable or reprogram??

[down_shift]

I have a 2006 Sport and would like to disable the "automatic" features of the HVAC system. I do not like how it automatically turns on the "recycled air" function when you lower the temp. Also I prefer the vents blow at your feet when using heat, but many times it overrides the vent selection and blows at your face.

Frustrating. How can you disable or reprogram all of these "automatic" features?

 

[cdoyle]

I have a 2006 Sport and would like to disable the "automatic" features of the HVAC system. I do not like how it automatically turns on the "recycled air" function when you lower the temp. Also I prefer the vents blow at your feet when using heat, but many times it overrides the vent selection and blows at your face.

Frustrating. How can you disable or reprogram all of these "automatic" features?

Well pushing the 'auto' button, so the light turns off, should stop it from choosing the vents for you.

But as for the recycled air, that's just how it is. As far as I know, there is no way to make it stop doing that.

I hate it too.

 

[toto]

The computer can be a bit rigid about the way it works.
Its behavior follows these rules:

- The fastest way to cool the air inside the car is to turn on recirculating mode, so that's what the computer does. (That way, you're cooling air you've already attempted to cool, rather than pulling in fresh - but probably hot - air.) Once the inside cools to the desired temperature, and you didn't mess with the recirc button, then the computer will go back to outside fresh air.

- The Auto control makes heat come out of the bottom vents, and cool air comes out of the dash vents. A mix of the two (to regulate the current temp) comes out of both.

A lot of people get frustrated trying to turn the temp down to the mid 60's or "Lo" if they want cool air, and then bump it up to the upper 70's or "Hi" if they want hot air. Actually, it works best if you leave it set at a certain temperature like the thermostat in your house, and then put it Auto and forget about it. In the spring and fall, sometimes the computer makes some bad choices about blowing cold air out the dash, but kicking up the temp setting a degree or two will stop that.

If you disable the Auto mode like cdoyle said, you'll get more control over fan speed and vent selection, but I think the temperature control is still a little awkward. It's not like the manual knobs cars used to have.

 

[Mark86]

There is definitely a way the dealer can reprogram the computer of your truck. When my parents got a new Lexus, the dealer gave them a checklist and one of the items was to have the recirculate activate automatically or manually. Both cars have the same computer so it can be done. Here is a link (scroll down to page 2, item #12) http://www.lexus.com/pdf/service/RX400h_LPS.pdf

 

[Fro-Runner]

I believe there is also an automatic connection between the moonroof and the auto air recirculation mode button. Whenever you open or tilt the moonroof then turn off and restart your truck, the computer automatically illuminates the non-recirculation lite on the button. I suppose the computer is thinking you are getting enough air into the truck by having the roof open/tilted.

 

[Spider5]

There is definitely a way the dealer can reprogram the computer of your truck. When my parents got a new Lexus, the dealer gave them a checklist and one of the items was to have the recirculate activate automatically or manually. Both cars have the same computer so it can be done. Here is a link (scroll down to page 2, item #12) http://www.lexus.com/pdf/service/RX400h_LPS.pdf

Any idea how the changes are made?

 

[down_shift]

Good feedback, guys, but no luck on disabling the auto?? BTW - the only way to turn off "auto" is to select a manual fan setting. Hitting "auto" does nothing to turn it off.

To be more specific on the desire of my request, all I want is have your typical "vent" for these nice fall mornings without hitting 7 buttons to achieve this. Scenario: It is 50 degree outside and I want the following "low" temp, "low" fan, and "floor" vents. This is nearly impossible. First is to select "low" fan to turn off the auto mode. However, as you lower the temp down to "low", at 67 the vent goes from floor to the spit of floor/dash, then at 66 it goes to all dash. Then at low, the recycle turns on and the fan goes from "low" to "full". So now you have 65 degree heated air blowing full blast into your eyes.

Very annoying. There has to be some code to turn this off.

 

[cdoyle]

However, as you lower the temp down to "low", at 67 the vent goes from floor to the spit of floor/dash [/B]

If auto is off it shouldn't do this.
Mine doesn't, I use just the dash vents all the time, no matter what the temp, or fan speed. I've never had it switch to another with the auto light off.

 

[down_shift]

If auto is off it shouldn't do this.
Mine doesn't, I use just the dash vents all the time, no matter what the temp, or fan speed. I've never had it switch to another with the auto light off.

It must be something different with the 04' to 06' model year or related to the sunroof option as stated earlier. I don't have a sunroof (or wanted one when 6'-4" and 210. Not much room in this truck as it is.....).

I tried it again driving into work this morning. "Auto" light is off. As the the temp to moved to "low", the computer changes to recycle and vents in steps from floor, floor/dash, to dash.

 

[Spider5]

It must be something different with the 04' to 06' model year or related to the sunroof option as stated earlier. I don't have a sunroof (or wanted one when 6'-4" and 210. Not much room in this truck as it is.....).

I tried it again driving into work this morning. "Auto" light is off. As the the temp to moved to "low", the computer changes to recycle and vents in steps from floor, floor/dash, to dash.

Same as the 05.

 

[down_shift]

Almost forgot another grip with the controls, and this one is bigger than my morning ritual of several steps necessary to get to obtain unheated

 

[Spider5]

Mark,

Any ideas how this can be changed like in the Lexus you indicated. I've changed the door lock options, is there a button combination programing that you or your parents saw when they programmed the 400h HVAC or is it some kind of hand held device?

 

[Mark86]

Mark,

Any ideas how this can be changed like in the Lexus you indicated. I've changed the door lock options, is there a button combination programing that you or your parents saw when they programmed the 400h HVAC or is it some kind of hand held device?

You can't change that by yourself. The dealer has to plug a computer into the car and change it through there.

 

[Spider5]

You can't change that by yourself. The dealer has to plug a computer into the car and change it through there.

Bummer, wonder if you can buy the computer.

 

[Iron Clad Lou]

I've got an 04 and I have no problems with this. Everytime I get in the truck, its set at 66 degress, low fan, upper vent and feet, no recirculate.

 

[Spider5]

I've got an 04 and I have no problems with this. Everytime I get in the truck, its set at 66 degress, low fan, upper vent and feet, no recirculate.

Sounds like they changed it starting in 2005 models.

 

[cdoyle]

Sounds like they changed it starting in 2005 models.

I'll have to check my parents 06 and see if it does this.

Wow, I really don't like the 04 system, but the 05-06 sounds even worse.

I just wish they would give us a true 'non auto' option.

 

[Koz]

You can't change that by yourself. The dealer has to plug a computer into the car and change it through there.

Hi Mark,

The Lexus has a different recirculating control (on, off, and auto), you may not be able to have the 4Runner's programed. There is no documentaion that I can find. Next time I'm at the Stealers I will ask ( I hope never).

Koz

 

[pipspeak]

It's another example of how computer's screw everything up!

The auto air recirculation is indeed very annoying and apparently partly based on the "outside" temperature, even if that temperature is grossly inflated by the car being parked facing the sun and the air temperature is actually only 65 degrees! Auto reciculate also never seems to switch itself off. Once it's automatically on you have to manually turn it off.

Equally annoying is the "auto" feature that blasts you with air if the car's been sitting in the sun or been left out in the cold all night.

That's why I never use the auto feature and just set the temperature myself, although the downside to that is that there seems to be zero accuracy in what temperature air you actually get. Set it to 70 degrees on a hot day with the AC on and the air that hits you is about 60 degrees. Set it to 70 degrees on a 70 degree day when the engine is warm and the air that hits you is about 80 degrees. I long for the days when I could just get plain old fresh air in the cabin without having to open a window.

It's very annoying... but not as annoying as the faint whistling sound my blower makes on low speed!

 

[Falls]

I don't care for how they are set up either in my 06.