Air recirculation automatically shuts off

[geirhr]

See https://goo.gl/photos/3Ajk4UyXAVVMEAYZ7 for video showing the problem.

 

Whenever I turn on the recircualtion of air it will faultly shut off by itself after a random number of seconds. Mostly it seems to shut off after around 20 seconds, but the number of seconds vary from 2-3 seconds to several minutes or never (working correctly). This is very puzzling and even the local Skoda repair shop cannot figure out the problem with their diagnostics suite.

 

The car has the ability to automatically turn the recirculation on and off by analyzing the outside fume level, but this feature is disabled in the menus. Furthermore the manual states that the air inside the car is continually monitored and will automatically shut of the recirculation if the level (of CO2?) is dangerously high. Could it be that this sensor is faulty and to blame?

 

Any thoughts or experience that you have regarding this problem?

[radiognome]

There is a post on this where others said theirs were also disabled, including mine.

Yes it does this. Quite disturbing.

[geirhr]

There is a post on this where others said theirs were also disabled, including mine.

Yes it does this. Quite disturbing.

 

Sorry, by disabled I meant not checked. I can select to check it in the menu and then (in theory) the car would automatically start and stop air recirculation based on diagnostic of the outside air. This is however not the problem. The problem is that manual control of the air recirculation button is not working properly. When I press the button the air recirculation starts working as intended, but instead of staying on it switches off after some random time. I suspect this is maybe due to some faulty sensor that is monitoring the air quality inside the car, but diagnostic test by local Skoda repair shop could not detect any anomaly in the error logs. So presumably the car believes that it is correctly turning of the air recirculation for some reason and does no reporting of why.

Edited 15 January, 2017 by geirhr

[radiognome]

Yes, I am talking about the same thing, sorry for not being clearer.

[Legacy]

I started the other thread (http://www.briskoda.net/forums/topic/416772-recirculate-mode-button-issue/#entry4753486).  I have since had my car serviced and raised it with the garage.  They said that it was working as intended and will switch off recirculation when the outside temp is below 5 C.  They mentioned another two conditions which are on my invoice but I can't remember.  Possibly something about engine temperature being too low and the heated rear windscreen being switched on.  I'll dig out the invoice.

 

In any event, they are incorrect about the outside temperature seeing as mine will switch off recirculation at temperatures higher than 5C.

Edited 16 January, 2017 by Legacy

[doublev]

Do you fiddle with AC after turning recirc on?

AC is turned on as soon as you start recirc. If you turn off AC after that, recirc will also turn off after couple of seconds. Then you need to turn on recirc again without AC and it should stay on. It is like that on all VAG cars for years (friend has Seat from 2006, same behavior). It is there to prevent fogging the windows while recirc is on.

[Legacy]

My AC is always on so its not an influence on the behaviour of the recirculation switch in my case. 

[geirhr]

The fault with recirculation is not connected to the AC. The recirculation turns itself off by itself after a random number of seconds regardless of the AC running or not. And to be extra clear about the problem I am not referring to the first time it is turned on when it turns itself off immediately, but the fact that it does not stay on after the second and later press on the button.

[countryboy]

I wonder if anyone can connect a data logger like VCDS to your car and monitor the heating/aircon channel to see what the system is seeing and doing.

Ian

[RickTT]

The fault with recirculation is not connected to the AC. The recirculation turns itself off by itself after a random number of seconds regardless of the AC running or not. And to be extra clear about the problem I am not referring to the first time it is turned on when it turns itself off immediately, but the fact that it does not stay on after the second and later press on the button.

 

 

I will try to replicate on mine.

[RickTT]

Ok - there are plenty of variables here, ambient temp, engine temp, oil temp, engine load etc..

 

However i have replicated the process you are doing with fan speed and climate control temp to see if like for like.

 

My results - ambient temp 8'c, cold engine (not used for 4 hours.)

 

My air re circle does not turn off -

 

2 Tests -

 

Test 1 - Auto recirculation enable from the heating menu TICKED>

 

The first press of air recycling is auto canceled due to the auto recirculation mode enabled on my car.  A second press overrides (this is covered in the thread above.)

 

 

Auto recirculation disabled (un ticked)

 

 

 

I will test in again on the drive to work and see if its the same results as above..

 

Thanks

Edited 18 January, 2017 by RickTT

[eksa]

i received my my18 car this week and i am also having this problem which is very disturbing.  it is very annoying to check the recirc. button frequently.   it shuts itself of even when theres no mist in the windshield or even when the ac is on.  it gives the pollured outside air into the car.. could you solve the problem?

[geirhr]

The problem has been identified, but no fix will be given. There is a measurement of water vapor in the air circulation. If the vapor level is too high the recirculation of air is shut of as a safety precaution to prevent dangerous fogging of windows. This is why the recirculation of air functions great for me 9 out of 12 months in Norway, but not in the 3 winter months when the windows gain fog. 

[eksa]

problem is it shuts off when the air inside is dry,  no fog on windows at all..  my previous car octavia was shutting it off when visible fog on windows started...it was working fine..  but this one is not..

i think i may try covering the humidity sensor with a small sticker or something..

Edited 8 December, 2017 by eksa

[geirhr]

On 8.12.2017 at 15:16, eksa said:

problem is it shuts off when the air inside is dry,  no fog on windows at all..  my previous car octavia was shutting it off when visible fog on windows started...it was working fine..  but this one is not..

i think i may try covering the humidity sensor with a small sticker or something..

 

Do you know where this sensor is in the car? I would also like to cover it up somehow or encapsulate it so it does not trigger because of moist air inside the car. Like you I have no fog at all on the windows when the sensor triggers, but I do concur that the air is slightly moist.

[Conor9]

On ‎18‎/‎12‎/‎2017 at 19:49, geirhr said:

 

Do you know where this sensor is in the car? I would also like to cover it up somehow or encapsulate it so it does not trigger because of moist air inside the car. Like you I have no fog at all on the windows when the sensor triggers, but I do concur that the air is slightly moist.

 

Hi,

any update on an override for this issue? It is very disturbing to find an old diesel in front of you spewing exhaust into the car when you thought  recirc was engaged but the car has over-ridden it.

 

It's completely stupid to had a mode to auto regulate the recirc and then to still interfere with it when that mode is not engaged. Effectively there is no different mode - the car is always making an automated decision. I would like to get a software fix to this really as I don't agree it's working as designed. I suggest it is a mistake. 

 

Did the humidity sensor trick work? If so can someone share it's location?

 

thanks

 

[eksa]

No, it didn't work, it still shuts off recirculation automatically.  It does it if the outside temperature is below 5 degrees,  if it is over 5 degrees and ac is on it doesn't do it.

So In winter it is very disturbing to keep an eye on the recirculation button. The only solution seems modifying the software, but couldn't find anywhere that did it.