# Climate Control Auto Randomly Turning Off



## Burrell (Oct 1, 2006)

I have noticed that sometimes the climate control Auto button light keeps going out on its own both with and without the AC on. I turn it back on again and it might go off again straight away or in 10-15 minutes time. Its a bit puzzling has anybody else noticed this ?


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## iknight (Jul 4, 2007)

Only in as much as I often turn the Auto button off by accident when I turn the heated seat up because the buttons are very close together.


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## Chippy_boy (Jan 15, 2008)

Burrell said:


> I have noticed that sometimes the climate control Auto button light keeps going out on its own both with and without the AC on. I turn it back on again and it might go off again straight away or in 10-15 minutes time. Its a bit puzzling has anybody else noticed this ?


Strangely, I have noticed exactly the same thing with my new 2.0T. Did you ever get to the bottom of this problem?

Thanks

Chip


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## ginger69 (Jan 3, 2008)

Yes,

Same problem here as I've mentioned elsewhere.

No solutions to offer......just gonna whine to my dealer about it when it's first service comes up......


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## cedwardphillips (Sep 6, 2005)

I may be wrong but you have a roadster and the climate might operate like the climate on the A4 cabs. On the A4 cab, the car remembers the a/c settings from the last time the hood was down and reinstates them the next time you drop the hood. if you heave the roof down today for example and switch the climate off, the next time you put the roof down the climate will switch off. I discovered this when i used to run a cab because i thought it was broken - whenever i put the roof down it would go to off or 25C on my feet...
just a theory...


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## cedwardphillips (Sep 6, 2005)

cedwardphillips said:


> I may be wrong but you have a roadster and the climate might operate like the climate on the A4 cabs. On the A4 cab, the car remembers the a/c settings from the last time the hood was down and reinstates them the next time you drop the hood. if you heave the roof down today for example and switch the climate off, the next time you put the roof down the climate will switch off. I discovered this when i used to run a cab because i thought it was broken - whenever i put the roof down it would go to off or 25C on my feet...
> just a theory...


just sat in the one in the showroom - think i'm wrong....


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## ginger69 (Jan 3, 2008)

Yeah, I noticed that Burrell drives a roadster but mine's a coupe......

Thanks for troubling to look though...


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## Burrell (Oct 1, 2006)

Chippy_boy said:


> Strangely, I have noticed exactly the same thing with my new 2.0T. Did you ever get to the bottom of this problem?
> 
> Thanks
> 
> Chip


Yes, the problem is a faulty climate control/aircon control unit, my dealer changed this and its been fine ever since.


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## Fac51 (Feb 4, 2007)

cedwardphillips said:


> I may be wrong but you have a roadster and the climate might operate like the climate on the A4 cabs. On the A4 cab, the car remembers the a/c settings from the last time the hood was down and reinstates them the next time you drop the hood. if you heave the roof down today for example and switch the climate off, the next time you put the roof down the climate will switch off. I discovered this when i used to run a cab because i thought it was broken - whenever i put the roof down it would go to off or 25C on my feet...
> just a theory...


A very good explaination, and frankly a great feature - but unfortunately the TTR lacks this. My Auto is fine - one of the few things which hasn't developed a fault on my TTR yet (major touch on wood).


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## add017 (Jul 25, 2010)

I too had this problem. Bought 2007 roadster the end of last month and as you do, check everything is working once it's home. Thanks to this post noticed the climate control kept acting strangely. Namely the auto button wouldn't always come on, and the window demist button didn't provide the full blast of air. Further more if you pressed the top the thing would go off. Took it to the dealer Stockport audi today. Yes sir will put in on diagnostics. 1 hr later there is no problem shown. Right. Let me show the technician. Went outside showed him. Oh yeah definitely faulty will get one on order. Now booked for new controller.


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## jokskilove (Sep 10, 2013)

Reviving an old thread here.

Mine has developed the same problem. I've bought a used climate control unit on ebay, but the existing one is 8J0 820 043 A*G* and the new one is 8J0 820 043 A*Q*.

I've looked it up on https://audi.7zap.com/en/rdw/audi+tt+tt ... 19-819040/ - I can only find the AQ in here, and not the AG. The AG unit was also bought used when I had heated seats installed. From the visual inspection, they both have the same colours, buttons, and the numbers are displayed in celcius instead of fahrenheit. I can't make any sense of the data models mentioned on the page (PR-GS1,GS3+4A3+9AK+A8S)

Anyone have an idea if the two units are directly compatible, or need some coding? In any case, I'll need an Audi dealer to remove the component protection, but if coding is required, it might be less hassle to simply find another AG unit on the bay.


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## Tommy67 (Oct 22, 2013)

Hello,

Had the same problem, the issue is with the connections of the connector pins to the pcb. You can fix this by taking out the control unit, loosen the screws of the first unit and take it off. Next is to loosen the last 2 screws and take off the print board.

Now you can solder the pins at the back of the board, from the factory these are not soldered only pushed in.

Did it myself today and it solved my issue.

This is also covered in the item below:
https://www.ttforum.co.uk/forum/viewtop ... 9&t=518594

Hope this helps, it will save you some serious money.


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## jokskilove (Sep 10, 2013)

Thanks a lot! Will be a good opportunity to play with my new soldering iron


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## TT4LEE (Mar 8, 2015)

I'll have to give this a try. Mine seems to fail staying in auto mode in extreme conditions (very hot, very cold). If I use manual mode to get the car to a more normal temperature, it will then stay in auto mode.


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## badej (Aug 10, 2018)

TT4LEE said:


> I'll have to give this a try. Mine seems to fail staying in auto mode in extreme conditions (very hot, very cold). If I use manual mode to get the car to a more normal temperature, it will then stay in auto mode.


Same here! Will try soldering these pins


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## jokskilove (Sep 10, 2013)

Seems like my fat fingers didn't really like soldering all that much. The pins seemed pretty small, compared to my soldering iron. Came dangerously close to short circuiting some of the pins. Think I need a bit more technique and/or some tools better sorted for precision work...


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## jw250 (Oct 28, 2015)

Thanks for this. This problem has been driving me insane for about a year now. Audi quoting over £1000 to replace the whole unit was just not an option.

At first I was confused, wondering if it was the actual buttons (on the PCB) themselves that needed soldering. And that didn't make sense upon inspection. Then I re-read the posts and understood what they were talking about - the pins from the other side of the PCB which the large black-headed cable connects to. I had to employ a bit of common sense as there are three banks of push-through pin connectors from the other side of the board. Only one was of an anywhere near sensible size to attempt soldering. The other two were just too small. So I just went for that larger bank (perhaps 18-20 pins?)

I'm not really well practiced at soldering and the pins did seem very close together but I thought 'go for it!' and so I did (after practicing on a paperclip pushed through some old cardboard). It looked a mess but I managed not to short any of the pins. My soldering iron felt way too big for the task, but I was impatient and didn't fancy going out to buy more things.

Fitted it back (lights came on and it worked... PHEW) and tested for a good half an hour - which would normally easily be enough to have the dreaded AUTO button turning off and having to press a number of times to get it to stay on again for another 15 mins.

So I'm convinced it's fixed. And am very grateful to those that shared their discovery and repair tips. Thank you.


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## jokskilove (Sep 10, 2013)

On a related note, I replaced the climate control unit, but then I struggled for over a year with the heated seats working intermittently.

It turns out the three pins for the heated seats power were loose. They're clipped in as well, and not very well attached. Soldered the pins on both sides of the PCB, and now my ass is *hot* again! Wish I had done this earlier...


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## ebusch (Jul 1, 2007)

I've been experiencing this same issue. Does anyone know the type and size of bit needed to remove the screws to open up the climate control unit? I don't seem to have anything that fits.


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## ebusch (Jul 1, 2007)

ebusch said:


> I've been experiencing this same issue. Does anyone know the type and size of bit needed to remove the screws to open up the climate control unit? I don't seem to have anything that fits.


This is driving me crazy. I can't drive for more than about 5 minutes without it turning off. Does anyone have any more details about what's needed to fix this?


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## SwissJetPilot (Apr 27, 2014)

Two points about the Climate Control -

1.) A scan with a VCDS or OBD-dongle (e.g. OBDeleven or similar) is always a good idea to narrow down the problem.

2.) If the Climate Control unit is replaced, you'll need to run an Adaptation in order for the CANBUS to recognize the new unit. You can read up on this procedure in the HVAC Workshop manual which you can find in the KB under Section 7.

I'm not sure if a OBD-dongle devices can provide the Adapation required, but I do know the Ross-Tech VCDS can. Here's an older post on this same topic and a link to the KB -

*Climate Control Issue*
https://www.ttforum.co.uk/forum/viewtop ... &t=1872307

*FAQ - Audi TT (8J) Workshop Manuals & Repair Groups*
https://www.ttforum.co.uk/forum/viewtop ... &t=1833829


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## ebusch (Jul 1, 2007)

I'm just trying to open up the control unit to check the pins, but I can't figure out what type of bit is required to remove the screws that are holding it together. Nothing I have seems to fit.


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## SwissJetPilot (Apr 27, 2014)

From an older post on this topic by *Nick2000* -

*Middle vents not always working*
https://www.ttforum.co.uk/forum/viewtop ... &t=1860643

_so .... upon further investigation, it wasn't so much the middle vents were not always working - it was a case of the airflow path dial did not correspond at all to the icons. It wasn't an exact offset out either ( ie it wasn't a case of the LED indicator being 90 degree's out of alignment )

So whilst it was exciting playing hvac lottery :lol: , not too practical day to day...

Fault code read 08 - AUTO HVAC, 003 Mechanical Failure ( with count x 211 ). Not really that helpful in narrowing down the fault.

So - HVAC controller removed from car and I did the following actions :

1. To open up the controller there are 5 x Torx T6 screws on the back which need removing.
2. Then you are presented with one side of the pcb. You will see two more T6 screws holding the pcb in place, remove these.
3. Now on the reverse side, you can see all the IDC connectors are push fit into the pcb ( ie no solder )
4. Since the rest of the pcb looked good ( as in solder joint inspection ). I just soldered the push fit pins.
5. Cleaned the dust of the thermistor ( ie the small smt component in the fans airstream ) Whilst this wouldn't cause the problems I had, it may provide a quicker temp regulation
6. Re-assemble , test and now everything working as it should. 

Worth mentioning,

ESD precautions should be taken when handling the pcb - but if your soldering you already know this.

Removal of the HVAC controller:
The official way recommends using a hook tool. I found it much easier to use a straight slim trim removal tool - slide this in between the controller and the centre console ( all access from the front ). Do one side, it will pop out a bit , then repeat on the other side and pull forward.

Rotary encoder dials:
at first the problem suggested the dial itself. The assemblies have sprung brass contacts to contact a carbon track then also the same contacts also make the connection to the pcb. However there was no visual oxidisation on any of the contact points and there seemed even pressure on all the sprung parts. - However if you have problems it may be worth checking the contact pressure on these parts.

Fault codes
Upon re-assembly it now works, however time will tell and will do a rescan in a few weeks to see if the 003 Fault code returns - in case there are multiple issues._


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## ebusch (Jul 1, 2007)

Not my image, but I think that silver screw is one that needs to be removed to open up the unit. They look like 6-point torx/star screws me, but I don't have a bit small enough to fit. I was hoping someone would know the exact size.


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## SwissJetPilot (Apr 27, 2014)

See the previous post - *5 x Torx T6*

I believe the 5 you need to remove are marked with red arrows. The two blue arrows are for the fan.


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## ebusch (Jul 1, 2007)

I'm pretty sure the screws are all the same size, but that was the only image that I could find online that had a clear view of one of them. From your updated post I now know that they are a T6 torx. Thanks so much for the help.


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## SwissJetPilot (Apr 27, 2014)

When you get around to pulling yours apart, would you be so kind and post some pictures? I've gone through the forum and can't find any.


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## ebusch (Jul 1, 2007)

Sure thing. I'm not entirely sure what pins I'm looking for inside that need to be soldered, but hopefully once I get it apart it will all make sense.


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## ab54666 (Nov 18, 2019)

Interesting topic, mine works fine...... but....... does anyone else's light around the controls go out, think it's just on the one that controls the direction of air?


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## nick2000 (Oct 14, 2018)

ebusch said:


> Sure thing. I'm not entirely sure what pins I'm looking for inside that need to be soldered, but hopefully once I get it apart it will all make sense.


all the connectors in the HVAC unit are push fit into the pcb. This is not the most reliable contact method compared to soldered joints.

Once you have the unit open you will see all the connector legs go through the pcb and are simply push fit into the hole with the copper pad on the reverse side.

The idea is rather than rely on this push fit connection Is to solder the pin to the pad. There are lots of pins to solder but it doesn't take long. Using flux will help get a better joint than just solder.


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## ebusch (Jul 1, 2007)

There are 5 T6 screws that need to be removed in order to open the unit:








With those 5 screws out, you can pull off the plastic back plate of the unit revealing the circuit board underneath. There are two more T6 screws that need to be removed in order to take out the circuit board:








Once the circuit board has been removed, you can flip it over to see the press fit connectors along the top:








Here's a closeup of the larger connectors, which I assume is what everyone is soldering:


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## IPG3.6 (Sep 5, 2015)

Looks like a nice rainy day project to help future proof the unit


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## TT4LEE (Mar 8, 2015)

The instructions and photos added since I last visited the page are great. It is easy to pull the climatronic unit as described best to just use a plastic lever on one side then the other to loosen it. Easy to disassemble as described. I did solder the large pins (fairly easy) and tried then aborted soldering the smaller pins (way too difficult with a common sized solder iron).

No love, didn't make any difference with my auto button turning off sporadically.....

I wonder if the small fan unit might be worth replacing (throwing parts at the problem), as it draws cabin air across a sensor and cools the climatronic.... It about $30-50 so not a big investment...


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