Climate Control Auto Mode

[webb2000]

Hello all,

We've had our Verso 2.2 D-4D TR for a couple of months now, and generally have most things sussed.

However, since the weather has turned warmer a question has arisen about the climate control which the manual doesn't seem to give a straight answer to (well it does, but then it contradicts itself a couple of pages later!).

Basically what I'm wondering is whether when in 'auto' mode the a/c kicks in and out as required to cool the car to the temperature set, or whether the a/c button needs to be pressed also?

It seems if 'auto' is used on its own it doesn't cool very well (the colder you set it, the fans just seem to blow harder), and only if you press a/c does true cold air start blowing from the vents. If I have both lights illuminated does this mean the a/c is on all the time, or will it start and stop based on the temperature?

I thought the point of climate control was that you just set a temperature on the dial and then the fans, a/c and heater take care of the most efficient way of delivering that temperature.

Apart from that we're delighted with the car, well...coming from a Ford C-Max 2.0 TDCi (shortest, most miserable period of car ownership in my life) we would be!! This forum is a haven of peace and tranquility compared to the ffoc one for the C-Max!

Thanks.

[geoffb]

Have a Corolla Hatchback with climate control but I suspect the control operation is similar to the Verso. If it is then I think you will find that you need to press both Auto and A/C to engage automatic air conditioned air. With mine, if you only press Auto the climate control will work the best it can to the temperature you have set by juggling between unheated and heated air but if you are trying to get the temperature well down and/or want it chilled it can only do so much without A/C pressed i.e. just blow unheated air around the car.

Hope I've made sense and that's helpful ;)

[webb2000]

Have a Corolla Hatchback with climate control but I suspect the control operation is similar to the Verso. If it is then I think you will find that you need to press both Auto and A/C to engage automatic air conditioned air. With mine, if you only press Auto the climate control will work the best it can to the temperature you have set by juggling between unheated and heated air but if you are trying to get the temperature well down and/or want it chilled it can only do so much without A/C pressed i.e. just blow unheated air around the car.

Hope I've made sense and that's helpful ;)

Thanks, it is. That is generally the same impression that I got from messing about with it.

But, to quote from the manual (page 222).....

"In the automatic operation mode, the air conditioning selects the most suitable fan speed, air flow and on-off of the air conditioning according to the temperature".

From what you say, and my own experiments, it seems to suggest that it only actually does this when both the auto, and a/c buttons are lit together.

So on a cold day you would use 'auto' with no a/c, and on a warm day use 'auto' with a/c selected also.

I'm quite happy to do this, but I would prefer to be sure that the a/c is only kicking in as and when required in auto mode rather than wasting energy by being on all the time!

It would seem more logical that if the auto mode was unable to acheive the set temperature just by using 'normal' air that the a/c should turn on (and illuminate) on its own. Then if you didn't want the a/c on, just dial up the temperature until the light goes out. Or is this too simple?

[jamesholden]

On my Camry if I leave it in auto mode with the A/C light on, well actually as soon as you press auto the A/C light comes on but the A/C only kicks in if it's needed.

[man-bing]

Ok, lets see if i can shed some light on this topic.

In auto mode, selecting the desired temperature you need, will inturn control the fan speed and direction of where to blow, as in footwells or from the dash vents.

Depending on the temperature inside and outside of the car, the fan will either increase or decrease in speed to make it an ambient temperature. This will sometimes not make sense, when it's hot outside and to make the fan speed work slower the interior you need to set it at a higher temperature.

Now, when you select AC as well as auto mode, this all changes.

It will now try and heat/cooler the INTERIOR temperature only, by the sensor vent in the dash, mines just under the steering wheel by my left knee (well i think that's what it is )

Now it will still blow the air out either by the footwell or dash again, but it's now controlled by the temperature you set it at, so if you set it to 16c will will try and get the interior temperature to that temperature, so the fan might blow really fast to start with then slow down to that temperature when it's reached, once's it's got to the set temperature, it will try and keep it at that constant temperature, but if you open a window or door and the interior goes up, the fans will kick into fast fan again to cooler the interior down again.

Does this help at all

Bing

[webb2000]

Yes it does, thanks.

So basically in order to use the climate control to set and maintain a fixed temperature on a warm/hot day (and to avoid the fans going ballistic) both 'auto' and 'a/c' should be selected, and despite the a/c light being on continuously it is only actually coming on as and when required.

Have I got it right?

[man-bing]

Once you switch the AC is on, it is always on until you turn it off, bizarre as it sounds, so watch the fuel gauge drop really quickly espically if your travelling fast and it's hot outside.

The auto button only controls how/where to cool it down.

Don't forget, if AC is on, you need to switch on the interior circulate vent as well, all this does, is filters the air within the car, so it doesn't suck in air directly from outside so you can smell the exhaust from the car infront.

Bing

[webb2000]

Once you switch the AC is on, it is always on until you turn it off, bizarre as it sounds, so watch the fuel gauge drop really quickly espically if your travelling fast and it's hot outside.

The auto button only controls how/where to cool it down.

Don't forget, if AC is on, you need to switch on the interior circulate vent as well, all this does, is filters the air within the car, so it doesn't suck in air directly from outside so you can smell the exhaust from the car infront.

Bing

But doesn't this contradict what it says in the Verso manual on page 222....."In the automatic operation mode, the air conditioning selects the most suitable fan speed, air flow and on-off of the air conditioning according to the temperature"?

The 'having the a/c on all the time to maintain a constant temperature' scenario is what I was hoping to avoid.

[man-bing]

I'm sure it isn't, as i put it "always on", but trying to get it to stay at a constant temperature still has to drive the AC motor in the engine.

You can hear it when the car is idle, and you turn it on, it draws power to the motor slightly slowing the idle speed before it goes back to normal, and same as when you switch it off, it slightly over revvs before it slows down again.

It could be that the thermostat for the interior, will monitor the temperature accordlingly, and adjust the fan speed, direction and the temperature to maintain it, would switch the AC on/off as it needs it.

Either way, all i know, when i've got my AC on in my car, me driving at silly speeds on the motorway , it took me just over 200miles before i was empty, when i know i can get some 350-400miles out of it without the AC being on

I think i read somewhere, it uses a quarter of tank of fuel to keep the AC running from a full tank

Bing

[DaveSR]

This is the same on all cars although it might be called something different eg on my dads Seat Leon it's called ECON

Basically we all know what happens - but the reason why there is an on/off button for aircon is to save on fuel.

Having aircon on will cool the car down as we all know, but turning it off will just have it belting out more hot air as it is trying to cool it with no effect

[webb2000]

I'm sure it isn't, as i put it "always on", but trying to get it to stay at a constant temperature still has to drive the AC motor in the engine.

You can hear it when the car is idle, and you turn it on, it draws power to the motor slightly slowing the idle speed before it goes back to normal, and same as when you switch it off, it slightly over revvs before it slows down again.

It could be that the thermostat for the interior, will monitor the temperature accordlingly, and adjust the fan speed, direction and the temperature to maintain it, would switch the AC on/off as it needs it.

Thanks.

So, if I understand you correctly, in auto mode although the cold air from the a/c may be being switched on and off (as suggested by the manual), as long as the button is illuminated then it is actually running all the time.

Make sense?

[man-bing]

So, if I understand you correctly, in auto mode although the cold air from the a/c may be being switched on and off (as suggested by the manual), as long as the button is illuminated then it is actually running all the time.

All auto mode does, is try and make the temperature ambient.

If AC is off, then it will try and make the temperature as close as you set it, but if on a hot day, when the fan will be running on high.

Example, today is about 16c outside, but i've had to put the interior temperature to about 19.5c to make the fan blow quietly

If AC is on, then it will try and make the internal temperature constant to what you set it as.

[tosullivan]

general rule of thumb is if you want the internal temp to be lower than the outside temp, then you need the ac button pressed on, regardless of what you set the temp setpoint to

[shuffly]

Hi,

The climate on my verso is similar to all the others.

You can set the system on AUTO and then turn on the a/c if you want the car cooled on a hot day for example. The a/c is separate to the AUTO mode and they can be used independantly.

I leave my a/c on most of the time because it de humidifies the air in the car and this is handy if you dont want to mist up when its raining.

As regards fuel consumption, the Toyota system varies the amount of time the a/c compressor is actually on, so on a hot day is is almost constantly on, and when cooler, the system only runs now and again. If you sit in youre driveway you can hear it clicking in and out.

The actual fuel consumption penalty varies(hotness of day) but ive measured it at around 1-3 mpg

Or open a window and forget all this stuff :D

Ian