I have Octavia 2 PRE FL MY Sep 2017. It has single motor V71 to control re-circulation flap.

 

I have observed that re-circulation work fines (When switch off fresh air vent is open and when on fresh air vent is closed) when ignition is ON and engine is off but as soon as I start the engine fresh air vent closes irrespective of state(off/on) of re-circulation button.

 

My climatronic module is 1Z0907044S, I tried using FL climatronic module 5K0907044EK but same issue.

 

Please help.

Thanks

Could it be linked to a reverse light switch fault somehow? Reverse gear causes re-circ mode.  Are your reverse lights operating correctly and not stuck on?

Didn't notice any issue with reverse light.. and this is happening only while engine is running.

You may find the re-circ for reverse gear only works when the engine is running. I can't remember off hand. I'll need to check in my car later. Question is, where does the climatronic get that signal from, I would of guessed the source as the gearbox reverse switch.  

 

That was one idea that came to mind - reading your symptoms.

 

There was a posting in a Mk5 Golf forum, where the same symptoms existed and it was an aircon pressure switch with an intermittent fault, even though nothing was coming up in diagnostics.

Edited 19 July, 20178 yr by TheClient

Mine is DSG , does DSG have reverse gear switch?

 

I have reverse camera installed which picks signal from CANBUS.. if reverse switch had been the problem then the camera would have activated.

 

Aircon pressure switch means the solenoid sitting on compressor? I had this replaced last December.

2 hours ago, virgo79 said:

Mine is DSG , does DSG have reverse gear switch?

 

I have reverse camera installed which picks signal from CANBUS.. if reverse switch had been the problem then the camera would have activated.

 

Aircon pressure switch means the solenoid sitting on compressor? I had this replaced last December.

Right, well the switch probably routes via the CAN and then feeds other systems, so if the camera is not operating all the time and your reverse lights are going off,  it seems unlikely to be the problem.  I am not sure where the switch is on the DSG, but it will have a switch somewhere but not sounding like much traction there.

 

The pressure switch is not usually on the compressor usually on lines to and from.

There is normally a high pressure and low pressure switch. The post I am thinking was not specific, however the high pressure one is normally more often faulty.

 

Other than that, I'm out of Ideas.  

 

Are you talking about the pressure regulating valve on the compressor?

Thanks buddy I will get the pressure switch checked..

 

Yes i had changed pressure regulating valve on the compressor

On 7/20/2017 at 09:24, virgo79 said:

Thanks buddy I will get the pressure switch checked..

 

Yes i had changed pressure regulating valve on the compressor

 

Is it possible to identify faulty switch using Measuring block of VCDS?

I'm not sure of the measuring block I imagine there would be - some searching may turn up something. Also, if the pressure sensor was producing out of spec readings, one would normally expect faults to be produced e.g. lower limit for pressure reached etc.  But in at least one forum I read, they said the dealer had no faults.  I've no personal experience of any of this though... 

 

Here is a post.

 

I guess it is the pressure Sensor G65 they are talking about. Why it would cause re-circ mode I don't really understand.

 

http://www.vwaudiforum.co.uk/forum/showthread.php/58892-Air-recirculation-keeps-switching-on/page2

 

 

Observed 1 more thing..

 

Outside temp is 28 degrees, if I set climatronic to 20 degrees or below it goes to re-circulation mode irrespective of re-circulation button state.. but if I set temp to 22 degrees it behaves normally (can open close re-circulation flap).

 

Is this expected behavior?

2 hours ago, virgo79 said:

Observed 1 more thing..

 

Outside temp is 28 degrees, if I set climatronic to 20 degrees or below it goes to re-circulation mode irrespective of re-circulation button state.. but if I set temp to 22 degrees it behaves normally (can open close re-circulation flap).

 

Is this expected behavior?

 

This may be a country specific feature. When I have rented cars in hot countries I have noticed that recirculation mode is used with air con to bring the cabin temperature down quickly when first starting the car. See if the recirc mode turns off  automatically once the target cabin temperature is close to being reached.

38 minutes ago, pikpilot said:

 

This may be a country specific feature. When I have rented cars in hot countries I have noticed that recirculation mode is used with air con to bring the cabin temperature down quickly when first starting the car. See if the recirc mode turns off  automatically once the target cabin temperature is close to being reached.

 

Thanks.. I will check it out