Fresh air through vents without running heat pump.

The A/C enters automatic by default when you press AUTO, despite the light not being visible while it's automatic.

To temporarily manually turn it off, press the A/C button twice - first time to put it manually on, second time to manually off.

Then it will be off until you press the AUTO button again.

There's an option in the settings to not have the AUTO button apply to the A/C.

Exhaustively covered in this thread from last month:

Bugs? (A/C and auto-high beams) | PriusChat

And the remaining mileage indicator isn't very smart - it doesn't seem to adjust its "climate control deduction" based on whether the A/C is enabled, or any real load indicator, so don't look at that for an indication of whether the heat pump is engaged. (The car does know what the current climate kW load is - you can see it on a scan tool, or affecting the My Room power display - but it doesn't seem to use it for that range display).

 

Open some windows.

 

the software is programmed to reduce estimated range when you turn the fan on. they have done it that way for 13 years, no one knows why. the heat pump is not coming on.

 

I have noticed that if I select outside air and then turn the heat/ac off I can get some air coming through the vents by cracking a window just a little - no fan running.

 

If you do not want the heat pump to work and be only in ventilation, lower the temperature at the bottom of 15 degree Celcius and at this time, the indicator indicates LO.

When the temperature is at LO, the heat pump is stopped.