Hello All,

 

I have got a Skoda Octavia (59 plate), one day the AC just stopped working, went and got it re-gassed and it started working again then randomly a day later it stopped working again.

 

I plugged it and using VCDS I got a code on HAVC for Air Quaility Sensor Open\Ground, clearing the code just causes it to re-trigger, this give me a couple of questions?

 

Firstly if this sensor is indeed faulty then could it cause the AC to stop working?

Secondly, where the bloody hell is this sensor, I have read it maybe under the skuttle plate below the windscreen but it is definatley not there?

 

Any help would be very much appricated.

 

John

It may be that its been removed as you would probably see it under the scuttle panel.  Is there an empty connector there perhaps?

 

I had a similar error (9479189 - Signal Line for Air Quality Sensor B10A4 15 [009] - Open or Short to Plus) before I fitted one when I upgraded to a facelift climate panel in my pre facelift car (they are not part of the pre FL setup), but it made no difference to the operation of the AC (apart presumably from the auto shut off in noxious fumes).

 

If there is not an empty connector, then maybe no wiring at all for the AQS.  The easiest way to check that is to see if there is a wire in the G238 sensor pin in the relevant plug on the back of the climate panel (i.e. pin 4, connector A see:

http://workshop-manuals.com/volkswagen/golf-mk5/heating_ventilation_air_conditioning_system/heating_air_conditioning/air_conditioner/air_conditioning_system_with_automatic_regulation_quot;climatronicquot;/connectors_on_climatronic_control_unitj255/pin_assignment_for_multi-pin_connectors_a_b_and_c_on_back_of_climatronic_control_unitj255/)

 

Adam

Thanks for this Adam, I could not even see a conector for it.

 

Can you use VCDS to turn the sensor off so the car does not look for it?

 

Many Thanks

Possibly. But I have never tried that as I fitted one instead. And note its also part of the hardware as its a button on the climate panel so maybe less likely?

Yea, it is just odd as I do have the button on the dash so I would think it should have the sensor.

Yes it is odd but perhaps the climate panels are made broadly the same for the different specs and some buttons simply don't work. It is easy to pull out the unit and look at the wiring to see if its not fitted at all.

Remove the dash trim from the bottom, easing it off using a plastic trim tool or spatula. Then remove the three torx screws and it pulls out. Look for a wire to pin 4 of connector A as per diagram above.