Climatronic problem

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Seems this is going to be the first problem with the car. Anyone else had a problem with over active climatronic? I have to set mine at 26degrees or else I've got icicles hanging off the visors. It sort of works in that on a cold morning when set at 26 it will run the heater, but as soon as the sun starts hitting the dash and the interior temp goes up just a few degrees, on goes the air con. On a hot day the fan runs at 4 with seemingly little let up on the compressor - and the air coming out is freezing. In fact, the air coming out the vents must be around 1 degree it's that cold. Problem is even on a hot day with the temp set on 26, I still have to keep turning the air con on and off.

Does anyone know if they are calibrated and if you can alter the parameters- or just a fixed sensor?

[vwwv]

Yes, same issue with my 118TSI. It has been back to the dealer once already (one month old) and had the climatronic controller replaced. Didn't fix the issue though. Generally have to have the temperature set at 25 to 26, or turn the air-conditioning off, to make it comfortable in the cabin. Back to the dealer I suppose....

[kleung]

It sort of works in that on a cold morning when set at 26 it will run the heater, but as soon as the sun starts hitting the dash and the interior temp goes up just a few degrees, on goes the air con.

Hah! "Cold" weather in QLD. That'll be the day.

For the record, if the AC button is lit, the AC is running constantly, just at varying outputs, as it's not just controlling the cabin temperature. It's also dehumidifying, which is why the windows demist so quickly in winter with the AC on, regardless of the temp setting.

In fact, the air coming out the vents must be around 1 degree it's that cold.

It's possible that the output air is actually that cold, in certain conditions - and that will be by design. The temperature at the vent can be significantly different to the ambient cabin temperature, especially when the cabin temperature is significantly different to the temperature that you have set on the Climatronic.

There are a number of sensors that affect the way the Climatronic unit operates. There should be a diagnostic mode where you can inspect the various sensor readings. If you search around you should be able to find out how to get into it, and have a look at each sensor readout to see if one is not responding correctly.

I have the opposite problem with my R36 at the moment - the AC is not nearly cold enough. Last summer, on a 30C day in auto mode with the temp set to 22C, the fan was still blasting along at level 6 after half an hour of driving. A few weeks ago, just as an experiment, I set the Climatronic temp to 'low' in manual mode with the AC on, fan speed at 3 and only the face-level vents selected. After 15 minutes of driving, I was only just starting to feel cold. The outside temp was about 19C (according to the MFD), and the car hadn't been sitting in the sun. Not good enough. The AC in my previous Accord Euro coped with those 45C+ days that we had here in 2009 with absolutely no problems. My R36 is due for a service, so I'll have the dealer look at it then.

[guthrie]

Seems this is going to be the first problem with the car. Anyone else had a problem with over active climatronic?

I have the exact same issue. Spoke to the dealer about it at the first service...but they said it is operating normally.

My old 2007 Passat with the old style climatronic was always perfect at about 22 degrees. The new one needs to be 24 to 26 (or off) otherwise you freeze.

I have covered up the light sensor in the middle of the dash which has improved things slightly - it used to blast cold air on sunny days even if the inside cabin temp was low.

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thanks guys, seems it is a problem then. I'll talk to the dealer about it. The Tig worked great - set it to 23 winter and summer and all was good. Even on a hot day, it just gets too cold. Might have to just run it manually till it gets sorted. Be interesting to see how it works with auto off and adjusting the temp settings manually (not sure how it will work?).

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I have covered up the light sensor in the middle of the dash which has improved things slightly - it used to blast cold air on sunny days even if the inside cabin temp was low.

That's it! That's the problem sensor. I tried it today. It was a 26degree day according to the MFD. The car had been sitting mostly in the shade but I opened all windows for a minute while getting ready to take off. Put the windows up and took off. The air con set at 26 kicked in fans blowing at 4. I let it go and still about 5 k's down the road it's blasting out freezing air, fans still running on 4 and cabin temp about 19degrees I reckon. So I grabbed an A4 pad I had beside me and covered up that dash sensor. Within about 30 seconds the fans dropped to 2 and the air temp had adjusted and not blowing out the freezing air. I took the pad off again, and this time took a bit longer, but soon had the fans back up to 4 and freezing air. So put the pad back over and after a few minutes, I actually had to drop the temp control to 24 (which would normally result and fans jumping to high), but which this time, kept the fans running at 2 and nice comfortable air temp blowing out the vents and working as it should IMO.

So what does this sensor do, besides stuffing up the climate control? I suppose if I knobbled it, all hell would break loose and the car probably explode!

But thanks for the tip guthrie, that's definitely causing my problem. It works great with that covered up.

[R34]

I've had the same problem since my R36 was delivered in June 10
The dealer claims the unit is working as per design.
After extensive reasearch I have a tried and tested Climate Control Calibrator which after 15 months of faultless operation I am now prepared to bring it to the market.
The only problem is that it has failed UV testing as it was originally black
Price for the non UV rated model is 9c plus postage and handling

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LOL, I'll take two - always good to have a spare!

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Finally found out what this sensor actually does. Seems it is for Climatronic only and just measures amount and strength of sunlight. So I took it off today and did a bit of modification.

This is the little sucker out of its housing (talk about over engineering!):


The housing is VERY dark and even holding it up to the sun it's hard to see much light through it, so this sensor must be very sensitive (or it's picking up other rays in the spectrum). Even shining a torch light through it, you can see not much normal light getting through:


I was thinking of just keeping it attached to the harness, but dropping through the dash rather than clipping it back into the holder, but worried about damage etc. Didn't want to disconnect it as it would show a fault somewhere, so instead I just got some high temp black tape and put a strip on the inside of the housing. Put the sensor back into place in the housing, then put the housing back into the dash. Took it for a drive - fixed! Climatronic now working as it should (or at least how I think it should!). No need to keep turning air con off, can run it on 24 or 25 rather than at 26 and still having to turn the fans down. It is warm today about 29C, and left the car in the sun at the shops, got back in and with air con on 24 it ran the fans for a few minutes at 4, then dropped back to 3. I turned it up to 25 and fans dropped down to 2 (previously they would still be running at 4) and air just nice temp for today.

Thanks again for the tipoff guthrie! I owe you a beer.

[R34]

Is the sensor easy to get out of the dash?
Had thought of doing that but would prefer VWA to come up with a fix not me