This may have been answered but I can't find it. How does auto climate control work in relation to the ac button? When it's hot you sometimes need to turn on the AC but why is this necessary with auto climate control? Don't understand how the system works.
As I understand it when you use auto you dial what temp you want and the system will use what it needs to get that for you whether it be the a.c. or the heat.
Auto climate control works quite well in the winter with the A/C button off. Some folks use it that way during warmer times of the year to conserve energy. Me, I like my A/C on as soon as it starts to warm into the 60s.
So basically you have to turn the A/C button on when it gets warm, even with automatic climate control.
No. If you hit the AUTO button all you have to do is adjust the temp you want and it will get there on its own.
There does seem to be an opinion that after you have manually turned the AC off from auto mode, it will stay off even the next time you go into auto mode. IE you have to re-enable ac in auto mode manually the first time. I also seem to recall there might be a techstream configuration setting related to this behavior, so its possible different vehicles may actually have different behavior if this setting is configured differently. Rob
The Prius has a humidity sensor. I would imaging that it only runs the compressor when it needs to cool or remove humidity. I believe the a/c button/light (unless front defrost is on) has to be on for the compressor to run. I didn't realize the it had a sun load sensor. Since I tinted the entire windshield the fan speed in auto will go down to 1 notch instead of 2 as it did before. Electronic air conditioning -- An overview of systems found in today's hybrid vehicles - Auto Service Professional
The A/C button just lets you control whether it cools with air conditioning or just outside fresh air. It's useful if you want to save energy. With the A/C off, the auto climate control will just run the fan faster and faster to cool the interior, even if your set point is below the outside temperature (and thus it would be impossible to cool that much without A/C). The Auto button basically just tells it to adjust the fan speed, output vent mode, recirculate mode, heater core, and (if enabled by the button) A/C compressor to reach your set point. It will only engage the A/C if you've told it that it is allowed to.* *One exception; if you set the vent output to the foot & defrost mode, or if you press the front defrost button, the A/C compressor will run, even if the A/C light is off, in order to reduce the humidity of the air blowing across the windshield.
