A/C Auto function

[hotbrass]

When the Auto function is turned on, will the A/C compressor come on automatically if cooling is required? Or does the A/C button have to be pressed?

If it comes on automatically, then why doesnt the light come on the A/C switch to indicate the compressor is on?

Thanks!

[qbee42]

Originally Posted by hotbrass

When the Auto function is turned on, will the A/C compressor come on automatically if cooling is required? Or does the A/C button have to be pressed?

If it comes on automatically, then why doesnt the light come on the A/C switch to indicate the compressor is on?

Thanks!

To have the compressor run automatically as needed, you have to leave the A/C button on. Think of it as an "enable" switch. When it is off, the compressor cannot run. When it is on, the compressor will run as needed, at the required speed.

Tom

[rachaelseven]

The "Auto" only refers to the temperature control and vent position control. The AC button still has to be lit to enable the compressor, just like most cars.

[chrisj428]

Rachael,

Actually, on every other car I've owned with automatic climate control, depressing the AUTO button enables the a/c compressor as well. This is the first ACC-equipped vehicle I've owned (out of nine) which allows me to specifiy a/c compressor operation independently from auto vs. manual control.

It took me a minute or two to figure out the different logic, but I like it.

[yardman 49]

Originally Posted by rachaelseven

The "Auto" only refers to the temperature control and vent position control. The AC button still has to be lit to enable the compressor, just like most cars.

Maybe things have changed with the climate control operation on the G3s, but this is how it works on the G2s:

- If you turn off the climate control via the "A/C Auto" button on the steering wheel, and then press that same button again, the climate control goes into "fully automatic" mode, meaning that the AC will come on as needed, and the temperature will set to whatever you select via the "up and down" arrows under the Auto button on the steering wheel.

- You could then go into the climate controls on the MFD, and shut off the A/C compressor enable. Then when adjusting the temperature up or down the car will attempt to reach the desired temperature without using the A/C compressor.

- the A/C compressor on the G2s and G3s is a variable speed, all electric compressor. So the car can vary the speed of the compressor to produce more or less cooling. This is completely different from most cars, where the climate control will "blend" the cooled air with heated air to reach the desired temperature. This is both more efficient, and also allows the car to run the A/C when the ICE is not running.

- Lastly, if you have the NAV with voice feature, you can press the "talk" button on the steering wheel, and then say "68 degrees", or whatever temperature you desire, and the car will say "setting the temperature to 68 degrees". If the Auto A/C is off at the time that you do this, it will turn on. Although I find that I usually just use the steering wheel controls for this, it is pretty funny to do it when you have a passenger in the car!

Best wishes,

[rachaelseven]

Originally Posted by chrisj428

Rachael,

Actually, on every other car I've owned with automatic climate control, depressing the AUTO button enables the a/c compressor as well. This is the first ACC-equipped vehicle I've owned (out of nine) which allows me to specifiy a/c compressor operation independently from auto vs. manual control.

It took me a minute or two to figure out the different logic, but I like it.

My bad. Most of the cars I have owned had an AC button that was separate from the other controls, so I suppose that is what I saw as similar. At any rate, that's how it works on this one :-)

[peirhead]

Originally Posted by rachaelseven

The "Auto" only refers to the temperature control and vent position control. The AC button still has to be lit to enable the compressor, just like most cars.

I have been testing for this and it appears that even if the "Auto" switch is off, the system still tries to maintain the set temperature by varying fan speed...it is as if the Auto switch is really auto A/C, enabling the automatic humidity control.

[rachaelseven]

Originally Posted by peirhead

I have been testing for this and it appears that even if the "Auto" switch is off, the system still tries to maintain the set temperature by varying fan speed...it is as if the Auto switch is really auto A/C, enabling the automatic humidity control.

That is correct and my statement was incomplete. Auto mode controls the fan speed, fresh/recirculate, and vent position (face, feet, combo) to try to maintain the set temperature. Auto mode will also modulate the compressor, if you have the AC light turned on. With auto mode off, you can still set a temperature, but I think in that mode it can only really control whether or not to add heat from the heater core.

[Tideland Prius]

Originally Posted by peirhead

I have been testing for this and it appears that even if the "Auto" switch is off, the system still tries to maintain the set temperature by varying fan speed...it is as if the Auto switch is really auto A/C, enabling the automatic humidity control.

yes and no. If you turn off the AUTO function by pressing the fan speed, then fan speed is now manually controlled but the MODE (feet, head, feet & head etc) are still automatic.

If you touch both, then both should be completely controlled manually.