Auto Climate Control

Welcome aboard!

Yes, normal... I just learned this recently myself (thanks TP). If you start auto, then select a mode, it is still in auto and the fan speed will be adjusted automatically based on the cab temp and the Mode (ECO, Normal, Power) that you are in. You will get less fan speed in ECO mode.

There was a great thread on this just recently...

 

When you re-directed the air the auto temperature control stayed on. The auto light goes out unless you let it completely do it's own thing.

The system is a little hard to understand, it even acts differently if you put the car in Eco mode. It does a pretty good job though.

 

The light goes out to tell you that you are no longer in full "auto" mode - and unless the a/c button is "on" you will not have the automatic control of the ac compressor -- often needed in winter to keep the windows clear.

The "AC" button is like the "Econ" button on may other cars. it interesting that Toyota uses the "AC" on Toyotas and does not on any of the Lexus vehicles we have owned.

I order all of our company cars with auto climate control. Some of our employees not familiar with the systems are always playing with them -- I always say "just leave it alone". Give the ACC a few minutes and you will be comfy -- often they need to be set at say 72 in the winter and 70 in the summer. Most of the system also don't like to have the vents closed off on one side.

I will say that that putting the Prius in ECO mode does affect the ACC system to the point that I thought it was not working correctly -- the fan becomes restricted and I bet in the summer the AC compressor

 

Our personal cars all have auto climate control and my wife is always messing with the fan, temperature, airflow and fan settings.

 

LOL - my wife does too. I call her a control freak !!

 

I know -- I know ..... the fan is always an issue especially with the AC.

I find with most of the systems it is best to just move the control one degree.

In the winter ACC holds off on the fan until heat is available and then let loose -- others do the same with the fan and the A/C on hot days on start up.

But if you close vents or reduce the fan until the system has a chance to do its thing -- you will have to keep playing with it. And this is especially true if the sensors are only on one side of the car.

And ......duel or even quad systems don't solve the fan issue. It won't work with the fan turned down or the vents closed

 

Don't be surprised if you see a big mpg drop with heavy AC/heater use. It can really tank mpg when used heavily combined with short trips.

 

I don't see that. I note very litle difference.

 

Then you either don't have a large difference between the ambient temp and your desired temp or you just have not really looked at the issue with a critical eye. Using Eco Mode in the GenIII can help reduce the impact compared to a GenII but it is still there. Wait until summer and watch how many people start complaining about bad mpg.

http://priuschat.com/forums/gen-ii-prius-fuel-economy/97814-how-reduce-mpg-loss-because-c-use.html

http://priuschat.com/forums/gen-iii...5749-ac-commits-pre-meditated-murder-mpg.html