Octavia Elegance TDI PD - 2 litre diesel, June 2008, about 103,000 miles.

External air temperature display sometimes shows correct temperature , and sometimes drifts downwards, wavering between +15 degrees and -35 degrees.  Fault started about last November (i.e. 2015)

Sensor has been replaced - to no effect.

I've noted that during cold weather the cabin sometimes gets quite hot despite the climatronic system - then adjusts to normal afer a minute or so.  Climatronic controls look like this:

http://s264.photobucket.com/user/mark_eire/media/04082009268.jpg.html

Since the warm weather (from early May) the a/c has been intermittent. This intermittency doesn't relate to the external air temparature sensor - sometimes it works when the external air is indicated at minus 25 degrees.  But I've not noticed it fail when the external air is indicated at the expected temperature (generally 15 to 20 degrees).

Local independent garage investigated: refrigerant half missing, showed 195 grams when there should have been 525 grams; so refilled it to correct amount.

But a/c is still intermittent.  Garage confims that refrigerant is still present with correct quantity, pressure switch is OK, fuses are ok.  But when intermittent fault is present there is only 4.2v on connector to compressor.  All the other fans and vents operate as expected. Compressor operates correctly if fed 12v from the battery.

Another friendly garage printed out the relevant circuit diagram from Autodata.  This shows an "AC/heater air intake temperature sensor".  Is it likely that this is intermittently faulty?  It would explain the strange cabin temperature changes in cold weather.

Where is this sensor?

How would I test it?

Is the control module faulty?  How would I test it?

Is there any association between the external air temperature sensor and the climatronic system?  The circuit diagram would suggest not but Autodata evidently does not have a schematic for the external air temperature sensor.  It does seem to be a suspicious coincidence!

 

Is there a Skoda aircon expert in the Thetford area?

 

TIA

Just responded to the previous aircon post. There have been people discussing problems with the evaporator temperature sensor and a useful guide to getting at that sensor for a Fabia.  I want to know where this sensor is on an Octavia2 and how to get at it. It has been said that the fault causes intermittent operation of the aircon.

As a slight aside to this.......I didn't think Octavia came with a marked on/off button for the climatronic. It's usually a retro-fit / modification with a Stanley knife.

 

What colour does the temperature readout glow? Does the on/off LED light up, if so, what colour?

Has anyone found out where the evaporator temperature sensor is?

Sent from my Samsung Galaxy S7

A previous thread says it is under the centre top storage box above the dash.  See

Aircon sensor requires removal of dashboard?

Started by Controller, 06 Nov 2012 18:09

Hi guys, 

I have also intermittent aircon problem in my 2006 1.9tdi estate, and few ac specialist told that ac compressor is faulty, what do you think guys think about this compressor, it is a lot cheaper than brand one's

 http://www.ebay.co.uk/itm/371656171965?_trksid=p2055119.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT

I've posted before somewhere else but in case you missed it...

I have the same intermittent aircon on a 2006 1.9 PD and I've found that switching the ignition off and immediately back on while driving gets it blowing icy cold within a minute, odd.

In my case this doesn't work, i can get cold air without any logic. Sometimes it works for minute then turns off, then after another minute kicks in, sometimes works perfectly for an hour. Had a vcds scan, no fault codes present.