Air Circulation Mode (Always On)

No it doesn't maybe the switch is broken or something maybe it doesn't hold when you press it in the Toyota software you can make it so that every time you turn on the air it's in the recirculate position which is what you're in now to get into the fresh air position you have to manually select it by pushing the button or you could set it up so that every time you turn on the air the fresh mode is active first and then you move it to recirculate as you see fit with it not working at all going straight to off or straight back to recirculate or never coming out of a circulate would seem that the button might not be functioning properly just a guess I don't think there's a huge bunch of computer business to move the vent door but I could be wrong and if that's the case then the computer that runs your air conditioning and HVAC system could have a problem but I would certainly check the wiring to the switch and the switch itself first before I started looking at replacing the HVAC computer It might be a simple matter of pulling the switch and twisting two wires together and leaving them and being in fresh forever I almost never use resurrect except when I'm smoking weed in the car you know Cheech and Chong up in smoke all that yeah.

 

That's correct You're either going to be taking air from the outside from the cowl mixed in and blown on you or flowing through the cabin or you're going to go in recirculate mode which is going to close off the little flapper that lets fresh air from the cowl into the car thereby recirculating the air already in the car for the most part now your car is not airtight so you're not going to kill yourself with you know your exhaling air and rebreathing that and all that it's not like that but yeah you can't just turn those off well it's going to be in one position or the other I don't think there is an off i.e both of those green lights not showing I don't know where the air would come from then I mean there would be some trying to leak in around the windows and stuff because just the nature of manufacturing but I think even in my generation too it's going to be in recirca fresh It can't be in nothing.

 

Yeah I'm not sure about the disabled business yeah when the air conditioning in the HVAC system is off you shouldn't see any lights in the HVAC system if I'm not mistaken My persona was just out here for the last 3 years I just towed it away so I can't go out and turn it on and tell you but yeah that's right when the air conditioning HVAC system is dead or off there shouldn't be any green lights recirculate and all of that shouldn't make any difference because all you're getting is flow through ventilation if you're in fresh air if you're in research you're not getting that fresh air and it's not flowing through the cars you move forward or at least not as well as it would be Toyota flow through ventilation system is the thing you can read about it it's been around since the '60s so that is interesting that should not be doing anything with the system off that's correct I do believe why yours is sitting there on I don't know when you push the button while you're sitting there with the car off and that green light on either position showing when you move from research to fresh do you hear a vent door move should be pretty clear especially with the car off and no noise so I would definitely set my voltmeter up to check a parasitic draw and see if the AC fuse or the heater HTR fuse is causing you some draw as in you would remove the fuse and see the parasitic draw drop drastically the HTR fuse or the AC fuse or the what have you I don't think there's an HVAC fuse that way there you could get an idea of what you're up against but yes I don't think that's supposed to be on with the car sitting there off and nothing going on parked for the night No should not be a green light on the dash or on the display or on any of the buttons I don't think there should be any of that on everything should be at rest so maybe somebody has tapped something put some kind of a t-tap on a wire back under the dash to rig up I can't even imagine what but I think that is not correct.

 

Isn't turning the fan off with the air source switch set to inside air the same thing, or close enough? (Even the inside setting allows a little outside air in, for safety reasons.)

My semi-related pet peeve is that it won't let you turn the heat reliably off while fan is on, without having to fiddle with the temperature control.

 

I don't know I think in my Corolla out in the parking lot which is an '02 AE 111 when the air conditioner or the air fan flow through ventilation whatever the hell you want to call it is off that light on the recirc and fresh thing is not on I do not believe now I have to go out and turn it on in a few minutes when the light comes up I believe that's right nothing is on no lights the air conditioning compressor light is not on in the buttons not pushed or it is pushed in the system is off the blower fan off so everything in the HVAC system is now off I don't even think in our Gen 3 Persona the research fresh light stayed on but I don't have the car here to power up and see

 

The two lights on the recirculate/fresh-air button don't tell you about anything being 'on'. They just correspond to the two positions of the recirculate/fresh air door. The door's going to be in one position or the other, and the lights tell you which one it is.

Just having the door be in one position or the other doesn't make any air move or circulate. It's just a door. When it's open on the fresh side, then wind or car motion down the road can make some air flow.

The only thing powered in the car that makes air move is the blower. You can see what the blower is doing by looking at the bar graph on the right end of the LCD panel.

 

It's like having the little tab pulled on your window air conditioner You look through the cold air vent air blowing into the room and you pull that little lever you see the daylight show up It's adding a little bit of fresh air to the air that's being recirculated that's being sucked in through the front of the air conditioner through the filter a little outside air is mixed in with that brought across the evaporator and cooled and blown into the room pretty much the same in a car system more or less I just don't remember the recirc light or the fresh light being on in our generation 3 but we didn't spend a lot of time in it It was always broke so I guess that's why I don't remember in my Corolla there's nothing on pushing research and what have you with nothing on yields nothing happening turn the blower on and push the research and you can hear the damper move and it's predominantly recirculating the air in the car but the Toyota flow through ventilation system which has been around since the '60s is still allowing a little bit of fresh air to get in the car not around the door seals or any of that through the system that's designed to do that I would think it would still be the same on the Prius but may you never know I know in my Corollas my celica's and my early trucks they work this way moving further up the line into the 2000s well lots of things changed in Toyodadom.

 

The air that exits the cabin exits through the traction battery and cools it. So when the door is in fresh position the air flows more freely through the battery. (Even if you are not using the HVAC blower, when you're moving your speed down the road can make adequate airflow through the cabin.)

Putting the door in recirculate position can reduce the flow through the battery, but that isn't really something you need to worry about, as the HVAC and HV ECUs talk. If the battery wants more air your recirc setting will just get vetoed.

I generally keep mine in fresh position nearly all the time, and only poke the recirc button if some black-smoke-belching truck or swine hauler has pulled onto the road in front of me, and poke it back to fresh when they're gone.

 

Yeah that's what Toyota in the '70s called the Toyota flow through ventilation system It's like in the first part of your owner's manual or something like that I can go pull the 76 model owners manual and those words exactly are talked about Toyota flow through ventilation system.

 

That was a long time ago before traction batteries and things like that or even thought of I do believe

 

I'm not sure how much of the basic idea is even Toyota-specific. I can't think of any car I ever owned that didn't work pretty much the same way.

My first Prius was my first vehicle with electronic HVAC controls though. Before that, everything had pretty much the same three levers (or sometimes knobs) that moved three Bowden cables, that moved the outlet door, and the fresh/recirc door, and the temp blend door. And like a four-position electrical switch for the blower.

I didn't need lights to tell me which position the fresh/recirc door was in, 'cause I could look down at the lever.

But it is neat that the battery in back of a Prius can veto the recirc setting if it wants more air.

 

So we're saying the car can move the recert or fresh air lever based on battery temperature so all of a sudden driving down the road if the car feels like it needs more cold it'll put it in the rec mode or something along those lines. That's pretty cool because I've seen mine change before and I was wondering what the heck was going on but I didn't hear the fan running matter of fact I almost never hear my battery cooling fan running but anytime there's any heat it's ice cold in my car It's like a beer cooler in here in the summertime If I cracked the window steam rolls out and it's not from smoking weed

 

It's if you have recirc selected and the battery wants more fresh airflow, the door will move to fresh.

Because there's no lever on the dash controlling that door like my older cars had, you don't see any lever move.

I'm not sure if it changes the lights to show it's now in fresh rather than recirc position, or just goes to recirc position secretly. (Sort of like how it adds A/C in the defog modes without lighting the A/C light.)