hybrid air vent missing piece- important? and what is it?

you want it connected so you aren't venting hot air into the 12v area. not sure what the hole is for, emergency bypass?
i would think you could get the part from any dealer, salvage or eBay

 

We need one of our mechanical experts to chime in...I've never had that part out.
Wild guess that is liquid/water drop out (into hatchback) in the event water comes in there.
In rare cases (eg; car wash) water can get injected into those vents.
I am assuming that is on the underside/low point...not sure.

 

it vents out through the grille in your last picture, those are vent flaps on the other side

 

The square hole in the fender has a flimsy little rubber flap or curtain that is there so when fan stops blowing that curtain closes and kinda seals that vent hole.
When the battery fan vent air is pushed at it the flap opens and allows the venting air out of the hv box. And yes the flap to vent tube connection sucks it’s just kinda pointed at it not really sealed.
Whenever I see stuff like that I realize Toyota had a reason to do that and then I move along.

The reason that vent is missing is most likely the hybrid battery has been removed and rebuilt and the Butch that did it was to lazy too replace that part which is very bad as the battery vent fan runs all the time at low speed so no battery fan=very hot battery=premature battery failure.

Craig’s list whack a mole battery repair with tail light warranty. Keep an eye on the hybrid battery charging and discharging behavior.

It would be a very good idea to buy a Prolong hybrid battery charger.

 

Nothing to worry about. They are all like that. The fan blows cool air into the top of the battery. It then flows out the bottom of the battery and into that piece, where much of it is directed to the outside of the car through the wall vent. The opening in the plastic allows some "warm" air directly into the 12v battery area.

 

You have to pull that off to replace the battery also. Could be that. It’s screwed in if I remember correctly.

 

Yup, but the problem in my case is that whenever it rains or the air is humid, that opening in the plastic throws warm air on the 12v battery and causes condensation on it. Every time I see that condensation, after few hours, my Prius throw a P0aa6 isolation fault code. I reset it and it drives like new when there is no rain. There is no pool of water under the 12v battery so there are no leaks. There is only condensation on the 12v battery that causes this. Is it okay if I cover that opening or is there any other solution? Maybe using a 12v battery cover or is it a bad idea? Thanks

 

A P0AA6 code is for the High Voltage system only. The "condensation" you see on your battery is likely not 'typical' condensation at all, but actual small water drops in the HV battery cooling air stream. I've worked on many HV batteries. On some of them, I've had water come pouring out of the ductwork when I disconnected it. This is usually caused by water leakage along the hatch seal area, which runs down the area behind the trunk side panels and gets into the fan/ductwork. It then becomes part of the cooling air stream and you end up with water in the HV battery. Very likely, that is what is giving the P0AA6 code. I have some photos of one of these batteries. I'll try to find it. When I removed the passenger side trunk panel, the insulation was absolutely soaked. Water all over the battery and in the ductwork.

Found them...Here's a few photos of the top of one of those batteries.

 

Wao. great. it can be actual water drops on the 12v battery. Please allow me to get a little more help from you by asking a few more questions. I tried two methods.

1) The car was parked outside for the whole night and it rained for 1 hour, did not drive it in rain. After the rain, I checked there were no water drops on the 12v battery. The next day, I opened the hatch and there were these droplets on the 12v battery. This means these droplets form after the rain has stopped for a few hours. I pushed the start button and the red triangle with p00a6 showed. I wiped the 12v battery clean with a cloth, reset the code and the car gets into the ready mode and runs like a champ till the next rain.

2) I was driving in heavy rain, the rain stopped, I got home, opened the trunk, and saw no droplets on the 12v battery. After 10 hours, I rechecked, and there are water droplets on the 12v battery again. Thus, again I have to reset the code to get it into the ready mode.

In the first case, the car was not even on, so how can water be introduced into the HV cooling air stream if the HV fan is not running? I can assume that in the second case, water can be introduced as the HV was running while driving.

Secondly, why there were no droplets on the 12V battery immediately after the 1-hour rain in both cases? The condensation formed on the 12v battery is always after few hours. The code always shows up only when the 12V battery and its little black buddy just beside it are soaked in water. I'm puzzled really. It clearly means that if it is raining and the 12V is dry, there will be no codes.

I have already seen youtube videos for water leakage and applied silicon on common leakage points but the area under the 12v battery and the spare wheel is dry and there are droplets only on the 12v battery (It's not the battery acid, no smell). My theory is that if there is water on the HV battery, then the water droplets can show up on the 12v battery due to that little opening in the plastic air duct that connects to the wall above the 12V battery. What if I cover that plastic opening?

Thanks and please guide me what more exact areas to look for the leak if there are any with pics.. thanks again

 

I would remove the interior trunk trim side panels to expose the inner surface area of the trunk. Sit inside and have someone spray the exterior with a water hose so you can see exactly where the water in coming in.

I have a bunch of photos showing water dripping in from where the tail lights mount. If you've ever had a tail light removed/replaced, I can just about guarantee there's water leaking there. The seals on the taillight don't like being disturbed.

Also, water coming in from above where those rubber flaps are (on each side of the car). This one is due to the plastic retainer pieces that are attached to the steel body that hold the bumper in position. They have plastic studs that insert into square holes in the body panel. I have photos showing water leaking in through those penetrations. There should be little rubber gaskets present, but they get old or get missing. The photos were taken during normal rain, not a "hose shower".

 

Great. Will check that in a few days and let you know the findings. Thanks for the help

 

Update: stripped the trunk from side covers and got a person inside. Then showered water on the whole trunk and right side where the 12v battery is located, also rear tail lights. Not a single drop of water inside. Then two days later, another rainy day, just after the rain, I checked and no water on 12v or other parts.. After 8 hours, only condensation on 12v battery, all sides, mats and covers are dry and same isolation code displayed. No clue whats happening. One more thing, the first post of this thread shows a hole in the plastic thing, mine does not have this hole. Does it mean the 12v battery is not getting air from the cooling fan and causing the moisture?