Air quality sensor/automatic re-circulation

[lyubohar]

Hey guys. First post http://www.volkswagenforum.co.uk/images/smilies/smile.png

My manual says the car is fitted with Air Quality sensor (I guess it comes as standard with all A/C units?).

It is supposed to shut off outside air if the air quality sensor detects any harmful gases coming from the outside traffic. It doesn't seem to work on my car though - I can still smell the outside air coming into the car if tailing behind a bus or something. Also the recirculation button never lights up, unless I press it intentionally.

How does this work in your cars? Does the recirculation button light up on its own from time to time (when the air quality control kicks in)? Do you notice any smells from outside?

My car is a 2015 Highline, "Automatic air recirculation" is switched on from the A/C menu. I am driving with A/C on "auto".

Thanks

[lyubohar]

So nobody can confirm how this works on their B8? What I'd like to know before going to the service is:
- does your your Recirculation button light up on its own from time to time (when the air quality function kicks in)?
- do you smell exhaust gases from other cars from time to time?
Cheers

[Renars]

Its not that suffisticated more of a marketing trick.

[BenR]

The recirculation function is manual but I think it closes when you put the transmission in reverse so as to prevent exhaust fumes being sucked into the car.

It certainly doesn't self-close when you're behind a smokey diesel and I've never heard of that function on a VAG car. I wish it existed because I often close mine.

[lyubohar]

It certainly doesn't self-close when you're behind a smokey diesel and I've never heard of that function on a VAG car. I wish it existed because I often close mine.

It certainly does :) Or it should...It's in my manual. Also on my car menu. Also on my dealer's website as a feature.

[twinsen]

It certainly does :) Or it should...It's in my manual. Also on my car menu. Also on my dealer's website as a feature.

This air quality sensor for sure is working, but I completely don't know what kind of fumes it detects. I know it "works" because if it is unplugged, there is an error on the dashboard.
I live in very polluted area and I would like to have it working, but unfortunately it has never triggered air-recirculation. On the other hand, the humidity sensor opens the recirculator.
So we know it is able to steer it. Maybe some more sensitive sensor is needed here? I don't know also why the people don't complain about it too much. And VW doesn't care about those few which they have received.
My model is Passat MY2020, R-Line edition.

[lyubohar]

On the other hand, the humidity sensor opens the recirculator.
You mean your recirculation is triggered without you doing anything and the little lamp on the button lights on its own?

[twinsen]

You mean your recirculation is triggered without you doing anything and the little lamp on the button lights on its own?

No no - engaging the closed circulation can be done only manually - the air quality sensor does not work at all (despite it has coding for maximum sensitivity). But if you unplug it's cable - there is an error on the dashboard, that the sensor has failed.
That means, it DOES something, but most probably it does not react to the contaminated air, like in very polluted areas (with high concentration of PM10&PM2.5), and it also does not react to the exhaust gases from od diesel cars in front of you.
BUT, the humidity sensor inside the car is able to OPEN the circulation to prevent windows from fogging. Definitely someone would investigate it why it is happening that it can open, but cannot close for good reason (fumes).

[lyubohar]

I know the reason - safety. You get your windows all misty and you crash. :)
Anyway - my original question was could the Recirculation be activated by the car itself or mine is just broken. It seems it can't. As for the air filter - I think it does react to old cars in front of you, although a bit late - after you have already smelled the exhaust gas. At least this is my feeling from using the car for 4 years.

[MikeBz]

[Deleted]

[djjarvis]

I'll just add that I've observed this sensor working as advertised, although I was parked up with REST mode on.

Car in front started up and began to manoeuvre very slowly out of a space; lots of revs and visible exhaust. I heard the recirculation flap close and the pitch of the blower fan change. After the car moved away and the exhaust fumes had blown away, I heard it revert to outside air.

The recirculation lamp didn't light. It only indicates that the driver has manually selected the recirculation function.

It also says in the manual about this function only activating when there is no risk of windscreen fogging. Probably in winter there's little chance of it activating.