"Auto" Temperature control

[ToyDiehard]

Question about "Auto" Temperature control.

This past weekend we made a trip to Toledo Ohio. Sunday morning brought temperatures around 40 degrees F. The 4runner sat outside at the hotel (she wouldn't fit in the room, I tried).

My question is when we left at 7:00 am, I started her up, hit the climate control to "Auto" and nothing happened. No fan. I had to manually hit the defrosters and fan on. Later as the engine warmed up the "Auto" worked fine. Is there something Toyota did, that will not allow the "Auto" to work until the engine warms? Nothing I can find in the Manual.

 

[boston_kevin]

definitely nothing in the manual

In fact, there is very little about the AUTO climate control setting except that it may engage the recirc control for maximum cooling. I know that the AUTO will engage the A/C compressor, but I am not sure if this would affect warming up...

One thing to note though, I have seen if you touch anything (fan speed, vent direction control) other than temp up/down, the automatic control will turn off.

I'll have to try this tomorrow morning.

 

[G3 Trout Runner]

I've had the same thing happen to me. I believe the issue is when starting the car and using Auto to warm up when its cold outside the car knows you don't want cold air blowing onto you. Instead it waits till it warms up to fire up the fans. Hope this helps

G3 Trout Runner

 

[Hitman]

Yeah, a lot of vehicles with automatic climate control work the same way.... If you call for heat and the engine is cold, it does not blow cold air on you. Instead, the warm air will start blowing once the engine starts making enough heat to create warm air.

 

[ToyDiehard]

That's what I figured but I thought I'd ask anyway. Thanks for the help guys.

 

[the_josh]

if you notice when the car starts up the fan will be off and then it progressively goes up through the fan speeds until the car is warmed up, off-low-med-hi-supa hi. this is especially nice in hot weather so you dont get blasted with hot air. i used to never use this but once i got the hang of it i love it...

 

[Guest]

My GS400 is like this. If the air that it would be blowing inside the car is no warmer than the air that's already inside the air, then even if it's on "auto", it doesn't blow at all. As the car gets warmer and warmer, it starts to blow more and more air until it finally gets the interior zones the proper temperate.

Just leave it on auto and trust that it will do just as good as a job as anything.

My A/C even comes on gradually even though the car really doesn't need to warm up to do that. It does this as to not shock the people inside with a sudden cold blast of air, and to go easier on the A/C compressor.

It actually even automatically changes from fresh air to recirculating air depending on the polution levels outside the car. I was kind of surprised that people are saying their 4h gen 4Runners don't do this, as otherwise the feel of the climate control in the 4th gen 4runner feels very very similar to that in my GS400, except of course for the layout of the buttons/display.

 

[loudog2]

auto control

If I remember right doesn't the defrost kick on high anyway, even if the car is not warm yet. I can't remember, it's been a year since I used it. Also, why did toyota make the a/c turn on when you hit the Auto button?? Every time you hit auto you need to hit the a/c button off for your heat to work right.

 

[Mark86]

That is perfectly normal. Being I live in NJ and have very good experience with cold weather, I have learned to actually appreciate that. It is not pleasant having cold air blowing in your face on a 20 degree morning!! I have also found that the defroster kicks in automatically at random times. The funny thing is that it is usually accurate!

 

[Guest]

Re: auto control

If I remember right doesn't the defrost kick on high anyway, even if the car is not warm yet. I can't remember, it's been a year since I used it. Also, why did toyota make the a/c turn on when you hit the Auto button?? Every time you hit auto you need to hit the a/c button off for your heat to work right.

The A/C stays on most of the time regardless of whether it actually needs to heat or cool because the A/C compressor is capable of doing more than just cooling the air, it also dehumidifies the air! So yes, there is actually a sensor in Toyota/Lexus climate control systems that detects humidity level and based on that will turn the A/C on even when the heat is on to keep the air at a suitable humidity level. It may feel cool at first, but give it just a litttle while and you'll see that it's not crazy, it will put out hot air as soon as the engine is warm and the heater core has had time to react.

The same things happens with the defogger and defroster. It measures the humidity levels inside vs outside as well as the temperature levels, and is able to guess if there is condensation on the windows. From there it goes to work with the best mix of hot/cold air and humidity adjustments to reduce or eliminate the fog/frost.

I am speaking from experience of my 99 GS400 though... but from what you guys are saying, I suspect that the systems are very similar sans for possibly the polution sensor being absent from the 4Runner?

 

[Cliff s]

Heres is a trick I use when its hot(live in AZ). Open the back window about 1/2
to allow hot air to exit when you first get in the T4R. Then when the air gets
cold you can shut it. Leave the air on auto.

The same works if you have a sun roof.

Cliff s