Why can't I use the front window defroster and ECO mode at the same time?? I'm not even talking about the special button for front window defrost. I just want to set the mode button on defrost, but it always turns off the ECO button and I can't turn it back on.

because in Defrost mode, it's assumed you want to clear the windows as fast as possible, no?

Mods: EV mod, VVT-i emblem, sport pedals, OEM cargo mat, JDM Prius interior footwell lighting, Sylvania Silverstars 9003ST, DICE iPod kit, OEM all-weather mats, TomTom ONE v2, LED licence plate lights.

Same thing happens whenever you change the temperature control - high or low - in the extreme. I think TP's explanation is correct.

No, because I just am setting the mode to defrost, so the air is coming out of the windshield area, instead of coming out the front vents. I'm not pushing the designated "front window defrost" button. Also, I can't turn the ECO back on in that mode. I push the button and nothing happens.

It does not matter how you select defrost. Defrost disables ECO. That is the way Toyota designed it.

That sucks!

How do you set the mode to "defrost" without actually pressing the front defrost button?

I mean, if it's blow onto the windshield, it's most likely because you want to clear the windshield.

If you didn't want it blowing in your face, you would've chosen face/foot or foot only.

Mods: EV mod, VVT-i emblem, sport pedals, OEM cargo mat, JDM Prius interior footwell lighting, Sylvania Silverstars 9003ST, DICE iPod kit, OEM all-weather mats, TomTom ONE v2, LED licence plate lights.

I never have warm air blowing to my face, always to my foot. TCH is smart enough to do that itself, even with auto mode off. As TP said defrost is to clear windows.

Just keep pushing the "mode" button. It will eventually get to the defrost/foot setting. I want it to blow warm air on the windshield so it won't fog. But I don't need the a/c to be running as well, and I want the ECO to stay on! I don't know why this impossible to do.

ohhhhhhhhhhhh. That's not quite defrost but yeah I see what you mean. When I see the word defrost, I just picture the full version immediately. Sorry, my mistake.

interesting. To defog, you need the A/C anyway cause it acts as a dehumidifier so you can blow dry air onto the windshield.

Mods: EV mod, VVT-i emblem, sport pedals, OEM cargo mat, JDM Prius interior footwell lighting, Sylvania Silverstars 9003ST, DICE iPod kit, OEM all-weather mats, TomTom ONE v2, LED licence plate lights.