Hello,

as the temperatures are going up I saw that the climatronic on my 2007 1.9 TDI BPZ Superb (115HP) doesn't blow cold air regardless to my temperature settings. It just increases the ventilation speed but the air temperature that is blown inside is not cold at all.

I did a VAG-COM scan last evening but there is no fault detected on any of the car's ECUs.

Bellow is the one from Climatronic :

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Address 08: Auto HVAC Labels: 3U0-907-044.lbl

Part No: 3U0 907 044 A

Component: CLIMATRONIC S B5 C 2004

Coding: 17000

Shop #: WSC 73430

VCID: 3162CEEFFB7E81909E2

No fault code found.

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Than I had a more detail look only at the climatronic itself. There are several channels than can be monitored but unfortunatelly I am not an expert on this... so I cannot tell if they are right or wrong.

Should it need a refill with refrigerant ? How can I tell ?

Can somebody guide me to what should I check with Vag-com regarding climatronic misbehaviour ?

Thanks !

Best regards,

OviTripon

I think tis may be more of a general aircon question than an Climatronic problem.

So when was the system last re-gassed? If it's more than 2 years ago, I'd start there. Also, I'd go to Kwik-fit (but on no account allow them to do anything other than the regas) because if they can't make it blow 20Cdeg colder, they don't charge!

Thanks for the reply ! Good starting point, it was never re-gassed and I had no problem with it until now.

If needs to be re-gassed shouldn't it display a Low pressure refrigerenat error ?

Other ideas ?

Aircon typically loses about 16% of its pressure per year, without there being an actual system leak anywhere. Best practice, just to deal with that, is to regas every 2 or 3 years.

I had a similar problem last week - 1st day of warm weather. My local 'man' found a wire off the compressor - re-fixed and now all OK. He also regassed the system while at it - took 4gm gas - not bad in 7 yrs.

He also mentioned that the system cooling fan is liable to failure - no probs while in motion, but system can o/heat in traffic and then the whole lot shuts down..........

Thanks ! Did you scan the car for errors or you just search for the problem ?

I scan the car with Vag-Com and in my case there are no errors detected - like is nothing wrong but there is no cold air either (it doesn't matter if the car is in motion or not ) ....

I expected some king of failure to be detected in case of wires off / cooling fan problem / pressure loss but there is none.

When I start the car, the climatronic fan ( the one under the bonnet) is spinning regardless the settings (Off, Auto or Econ). Is this normal ? From what I read that fan should be spinning only when climatronic is on Auto mode, right ?

I have just regassed airco in Mk1 2006 Superb myself, after 7 years it took a full can of EZ Chill to get to reasonable pressure. About 2deg C improvement in temp post evaporator. I used Halfords EZ Chill kit, it is really simple to use though overpriced, there's a video somewhere on the net on how to use it. After returning the empty refrigerant bottle for a £10 deposit, total cost of topup was £44 plus I have now a pressure/fill gauge for the airco so I can check it anytime I feel like it. Next topup(s) on either car will cost me £24 (or less).

Also, while at it, I noticed you can monitor the various temperatures in VCDS, if you go to HVAC - measuring blocks, Group 6 and Group 7 have outside temp, inlet air temp, evaporator and outlets temperatures (separately for centre and footwell vents). This may come in handy troubleshooting faulty airco.

At full blast (press "auto" then blue button until climatronic says "LO" in temp field) after ~5min, the evaporator temp should be 7deg C or below, the centre vents will be at 7-11deg C (footwells if you enable them will be at evaporator temp easily). The airco in my car does about 20deg C-25deg C drop, note you have to double check fresh air temp in VCDS, as it can be much higher than you think (e.g. with 20deg C ambient the fresh air inlet was already at 29deg C- 31degC in a stationary car).

Re the various petrifying statements on how airco loses refrigerant with car age (EZ Chill is no better, "up to 10% per year"), my 10year old Octavia could still freeze the cabin without sweat and I never touched airco installation on that car. Superb has never been as chilling but I see no difference over 7 years, could be it was not fully charged in factory given I have just stuffed it with 1/2kg of refrigerant mix. I expect the extra 2deg I got from the topup to be noticeable only in the speed the cabin is cooling on a hot day. I'd say if the airco works fine, don't mess with it, though if it is not cooling enough obviously best to check various temps / coolant pressure and perhaps top it up if needed.

Edited 23 April, 201313 yr by dieselV6

Thank you for your feedback. Find the problem and solve it. Here goes:

Problem : no errors on Vag-Com or climatronic display but no cold air either.

Possible causes :

- air con fan not working : not the cause, there was no cold air even when the car was moving at a resonable speed

- pressure switch : checked, not the cause. ( I don't know to insert a picture, here is the link)

- compressor not working :

- compressor is broken or - not the cause

- electromagnetic clutch not working - cause.

- need to regass the instalation - not the cause

When I was doing the pressure sensor checks I could see clearly that everything indicated to a broken circuit between the sensor and the compressor. Of course there is no direct connection between those as the car's ECU is involved as well in this equation.

The compressor itself is quite a simple one, it gets only ON or OFF through the electromagnetic clutch. Basically if all the conditions are fulfilled ( ok to turn ON the compressor) the command to start the compressor will be issued through a relay ( 12V is applied on the electromagnetic clutch).

On this Skoda model the electrical diagnose is done up to relay's coil and not after it. So any broken wire after the relay's contacts will not be detected.

In my case the possitive wire to the electromagnetic clutch was broken somewhere near the compressor but this open circuit is not detected by the electrical diagnose performed by the ECU. There is no plausability check done to detect this kind of things either.

So, easy fixable problem, glad to find and fix it.

While I was there I replaced the brushes of the air con fan as well (they were worn but still working) to avoid investigating things a second time.

Edited 26 April, 201313 yr by ovitripon