Close

Results 1 to 18 of 18

Thread: Audi TT Air Con

  1. #1
    DF Admin maltloaf's Avatar
    Join Date
    Dec 2000
    Location
    Hereford, Here
    Posts
    16,086
    Thanks
    974
    Thanked:        1,291
    Karma Level
    1389

    Help Audi TT Air Con

    Hi all,

    A couple of days ago I bought an old Audi TT purely for a toy.

    It's done loads of miles but had cam belt/tensioners/water pump/pulleys etc all done within the last few weeks and goes like stink so I'm happy for my £1400

    Anyway, my air con isn't working. I found a cheap re-gassing service on groupon and took it in. When I went back in the guy said it was fully gassed already but he vacced it out anyway and regassed it to the correct pressure and showed me all the printouts from his machine showing amount of gas removed and the amount of gas/oil/uv replaced. He said it's not kicking in and it is likely to be the pressure switch.

    I got home and started reading up and found a load of useful info saying you can jumper out the four pin pressure switch to prove the system is working. I found my pressure switch and lo and behold it's actually a 3 pin variant and my trail of information dries up there.

    The compressor isn't engaging, the clutch seems to spin freely. I'd just replace the pressure switch to try but I'm not even sure of the right part number (there seem to be four variations)!

    Does anyone have any experience with VAG air con systems ? Any info, pointers, advice gratefully received.

    Thanks,

    malty
    Attached Images Attached Images
    PC gamer, steam ID maltloafs
    Xbox gamer, xbox live ID maltyuk

    i5 6600k @ 4.6GHz
    1660Ti OC
    16GB
    Lenovo Explorer VR
    Hyper X Alloy FPS keyboard
    LG Ultrawide IPS monitor
    Corsair Glaive mouse
    Corsair HS60 headset

    Xbox One S (mainly used for 4k bluray)
    Nintendo Switch

  2. #2
    DF Jedi Ashley's Avatar
    Join Date
    Dec 2008
    Location
    London
    Posts
    2,062
    Thanks
    3,527
    Thanked:        504
    Karma Level
    288

    Default Re: Audi TT Air Con

    Can't help as I know nothing about cars, but it's a decent looking car. I watched wheeler dealers a few days ago and they bought a similar TT.


    Sent from my iPhone using Tapatalk

    Thanks to Ashley

    maltloaf (9th May 2015) 


  3. #3
    DF MaSter ferarrifeet's Avatar
    Join Date
    Jun 2011
    Location
    uk
    Posts
    71
    Thanks
    17
    Thanked:        62
    Karma Level
    127

    Default Re: Audi TT Air Con

    i've got a vw golf with same problem, have changed pressure switch,still not working, i've been told it could be the valve which is part of the compressor,apparently this gets clogged up with metal shards and stop the aircon from working,also could be your fans, check they're working , haven't got round to looking at this yet but might be your problem.hope this helps

    Thanks to ferarrifeet

    maltloaf (9th May 2015) 


  4. #4
    DF Admin maltloaf's Avatar
    Join Date
    Dec 2000
    Location
    Hereford, Here
    Posts
    16,086
    Thanks
    974
    Thanked:        1,291
    Karma Level
    1389

    Default Re: Audi TT Air Con

    I've checked the fan controller and the two fans come on and off properly. I had read that the clutch can get clogged up but it seems to spin freely and I don't think the air con is requesting it which is why id suspect the pressure switch.
    PC gamer, steam ID maltloafs
    Xbox gamer, xbox live ID maltyuk

    i5 6600k @ 4.6GHz
    1660Ti OC
    16GB
    Lenovo Explorer VR
    Hyper X Alloy FPS keyboard
    LG Ultrawide IPS monitor
    Corsair Glaive mouse
    Corsair HS60 headset

    Xbox One S (mainly used for 4k bluray)
    Nintendo Switch

  5. #5
    DF Super Moderator
    evilsatan's Avatar
    Join Date
    Jul 2004
    Location
    Essex
    Posts
    20,355
    Thanks
    1,194
    Thanked:        3,437
    Karma Level
    1592

    Default Re: Audi TT Air Con

    Don't suppose you can scan it for error codes? Might specify a fault. Isn't the part number on the switch?

    Thanks to evilsatan

    maltloaf (9th May 2015) 


  6. #6
    DF MaSter ferarrifeet's Avatar
    Join Date
    Jun 2011
    Location
    uk
    Posts
    71
    Thanks
    17
    Thanked:        62
    Karma Level
    127

    Default Re: Audi TT Air Con

    does your compressor have a clutch? how old is your tt.?

    Thanks to ferarrifeet

    maltloaf (9th May 2015) 


  7. #7
    DF Admin maltloaf's Avatar
    Join Date
    Dec 2000
    Location
    Hereford, Here
    Posts
    16,086
    Thanks
    974
    Thanked:        1,291
    Karma Level
    1389

    Default Re: Audi TT Air Con

    Quote Originally Posted by evilsatan View Post
    Don't suppose you can scan it for error codes? Might specify a fault. Isn't the part number on the switch?
    Waiting for a vcds cable to arrive.

    Quote Originally Posted by ferarrifeet View Post
    does your compressor have a clutch? how old is your tt.?
    Yes it has an electromagnetic clutch which is why you would short out the pressure switch to force it to kick in but info on these 3 pin pressure switches seems a bit thin on the ground :-( it's a 2002 180bhp quattro model.
    PC gamer, steam ID maltloafs
    Xbox gamer, xbox live ID maltyuk

    i5 6600k @ 4.6GHz
    1660Ti OC
    16GB
    Lenovo Explorer VR
    Hyper X Alloy FPS keyboard
    LG Ultrawide IPS monitor
    Corsair Glaive mouse
    Corsair HS60 headset

    Xbox One S (mainly used for 4k bluray)
    Nintendo Switch

  8. #8
    DF Jedi coin-op's Avatar
    Join Date
    Mar 2001
    Location
    About
    Posts
    2,703
    Thanks
    73
    Thanked:        218
    Karma Level
    419

    Default Re: Audi TT Air Con

    I found this - I'm sure you have to.The trouble code was static open as described below :

    Unfortunately its not a true switch.. it produces a 20mS pulse whose duty cycle is dependent on refrigerant pressure (5% at 5bar to 90% at 35bar). The 'static open' suggests its not cycling. Check the connector is pushed home properly. The signal at pin 2 referenced to ground should show a voltage between 1 and 11 volts, outside this range suggests switch stuck open or closed.

    and

    The later pulse switch a previously described has, as far as I can see from the drawings, a rectangular connector with 3 pins in-line. You cannot test this by bridging, but you can verify pin 1 is ground and pin 3 has 12v approx on it when a/c is set to Auto & ignition on. Pin 2 is the pulse output.



    So if you have a scope you can look at pin 2 wrt ground and get an idea of what's going on.

    2 Thanks given to coin-op

    maltloaf (9th May 2015), Over Carl (6th June 2015) 


  9. #9
    DF Admin maltloaf's Avatar
    Join Date
    Dec 2000
    Location
    Hereford, Here
    Posts
    16,086
    Thanks
    974
    Thanked:        1,291
    Karma Level
    1389

    Default Re: Audi TT Air Con

    That's brilliant, no I hadn't seen it but it gives me something to look at.
    PC gamer, steam ID maltloafs
    Xbox gamer, xbox live ID maltyuk

    i5 6600k @ 4.6GHz
    1660Ti OC
    16GB
    Lenovo Explorer VR
    Hyper X Alloy FPS keyboard
    LG Ultrawide IPS monitor
    Corsair Glaive mouse
    Corsair HS60 headset

    Xbox One S (mainly used for 4k bluray)
    Nintendo Switch

  10. #10
    DF Admin maltloaf's Avatar
    Join Date
    Dec 2000
    Location
    Hereford, Here
    Posts
    16,086
    Thanks
    974
    Thanked:        1,291
    Karma Level
    1389

    Default Re: Audi TT Air Con

    Pin 2 floats roughly at 2.3v and changes a bit when engine revs change but settles again. It does dip below 1v occasionally but never for long. I don't have access to a scope but it would suggest it's doing something. Next target is the compressor and it's clutch mechanism if anyone can help. Where did you spot that info coin-op?
    PC gamer, steam ID maltloafs
    Xbox gamer, xbox live ID maltyuk

    i5 6600k @ 4.6GHz
    1660Ti OC
    16GB
    Lenovo Explorer VR
    Hyper X Alloy FPS keyboard
    LG Ultrawide IPS monitor
    Corsair Glaive mouse
    Corsair HS60 headset

    Xbox One S (mainly used for 4k bluray)
    Nintendo Switch

  11. #11
    DF Wh0re m4rkym4r's Avatar
    Join Date
    Nov 2010
    Location
    Blackpool
    Posts
    109
    Thanks
    11
    Thanked:        24
    Karma Level
    126

    Default Re: Audi TT Air Con

    Matly are those alloys 16", i may have a brand new one if you want it?

  12. #12
    DF Jedi coin-op's Avatar
    Join Date
    Mar 2001
    Location
    About
    Posts
    2,703
    Thanks
    73
    Thanked:        218
    Karma Level
    419

    Default Re: Audi TT Air Con

    Quote Originally Posted by maltloaf View Post
    Pin 2 floats roughly at 2.3v and changes a bit when engine revs change but settles again. It does dip below 1v occasionally but never for long. I don't have access to a scope but it would suggest it's doing something. Next target is the compressor and it's clutch mechanism if anyone can help. Where did you spot that info coin-op?
    [Only registered and activated users can see links. ]

  13. #13
    DF Admin maltloaf's Avatar
    Join Date
    Dec 2000
    Location
    Hereford, Here
    Posts
    16,086
    Thanks
    974
    Thanked:        1,291
    Karma Level
    1389

    Default Re: Audi TT Air Con

    Quote Originally Posted by m4rkym4r View Post
    Matly are those alloys 16", i may have a brand new one if you want it?
    yea they are 16". I'm trying not to spend too much on it if I'm honest, keep it cheap and dirty but how much would you want ?

    Quote Originally Posted by coin-op View Post
    [Only registered and activated users can see links. ]

    yea i've been in and out of there for a few days but not seen that particular post.

    I ran out of time this evening but the last thing I was doing was trying (and failing) to get the compressor clutch cable connector off. It's in a bit of a tricky location and didn't seem to want to unlock at all. I would like to force the compressor clutch on with a 12v feed and also test that cable. Hopefully I can get the damn thing off !
    PC gamer, steam ID maltloafs
    Xbox gamer, xbox live ID maltyuk

    i5 6600k @ 4.6GHz
    1660Ti OC
    16GB
    Lenovo Explorer VR
    Hyper X Alloy FPS keyboard
    LG Ultrawide IPS monitor
    Corsair Glaive mouse
    Corsair HS60 headset

    Xbox One S (mainly used for 4k bluray)
    Nintendo Switch

  14. #14
    DF Wh0re m4rkym4r's Avatar
    Join Date
    Nov 2010
    Location
    Blackpool
    Posts
    109
    Thanks
    11
    Thanked:        24
    Karma Level
    126

    Default Re: Audi TT Air Con

    Ill take some pictures of it to check that it is the same type, if you pay postage you can have it.

    Thanks to m4rkym4r

    corskey (10th May 2015) 


  15. #15
    DF Admin maltloaf's Avatar
    Join Date
    Dec 2000
    Location
    Hereford, Here
    Posts
    16,086
    Thanks
    974
    Thanked:        1,291
    Karma Level
    1389

    Default Re: Audi TT Air Con

    Wow great offer thank you mate
    PC gamer, steam ID maltloafs
    Xbox gamer, xbox live ID maltyuk

    i5 6600k @ 4.6GHz
    1660Ti OC
    16GB
    Lenovo Explorer VR
    Hyper X Alloy FPS keyboard
    LG Ultrawide IPS monitor
    Corsair Glaive mouse
    Corsair HS60 headset

    Xbox One S (mainly used for 4k bluray)
    Nintendo Switch

  16. #16
    DF Jedi blacksheep's Avatar
    Join Date
    Jun 2006
    Location
    Manchester
    Posts
    3,877
    Thanks
    87
    Thanked:        265
    Karma Level
    513

    Default Re: Audi TT Air Con

    Sure it's not the hairdryer that's on? It is a hairdresser car

  17. #17
    DF Admin maltloaf's Avatar
    Join Date
    Dec 2000
    Location
    Hereford, Here
    Posts
    16,086
    Thanks
    974
    Thanked:        1,291
    Karma Level
    1389

    Default Re: Audi TT Air Con

    I wondered why the toolkit consisted of curling tongs and a scissor / comb set
    PC gamer, steam ID maltloafs
    Xbox gamer, xbox live ID maltyuk

    i5 6600k @ 4.6GHz
    1660Ti OC
    16GB
    Lenovo Explorer VR
    Hyper X Alloy FPS keyboard
    LG Ultrawide IPS monitor
    Corsair Glaive mouse
    Corsair HS60 headset

    Xbox One S (mainly used for 4k bluray)
    Nintendo Switch

    2 Thanks given to maltloaf

    blacksheep (10th May 2015), Over Carl (6th June 2015) 


  18. #18
    DF Admin maltloaf's Avatar
    Join Date
    Dec 2000
    Location
    Hereford, Here
    Posts
    16,086
    Thanks
    974
    Thanked:        1,291
    Karma Level
    1389

    Default Re: Audi TT Air Con

    Thought I'd update this thread with a resolution. After going through a few other faults (ECU flash and also changing my cam chain tensioner) I got back to looking at my air con.

    no fault codes were present and after deciphering wiring diagrams in both Polish and German, I couldn't find any fault, which all pointed to my fan controller being faulty.

    Impatient as I always am, I got another FCM from a local breaker but it wasn't quite the same part. I tried it anyway and the result was exactly the same. Cooling fans running but no air con.

    I then came across a bit of a bodge in the cable to the FCM, someone had been there before !

    I found a blue scotch lock going off to directly supply the fans via a 30a fused supply. The wheels started turning in my head and I re-read the wiring diagrams, which suggested there should be 2 12v feeds into the FCM and when I tested I only found one.

    I couldn't for the life of me figure out why the bodge had been installed. All of the feeds were intact coming from the battery fuse box (which does all the high current items like alternator, fans etc) but still I only had 1 12V into the FCM.

    I then found a broken wire, which I initially thought the bodge was bypassing but now I realise the bodge itself had failed at this point, and the new 30A feed instead of just going to the fans was actually meant to be going to the fans AND the FCM.

    I connected the little stub of broken wire up to the existing cable and bang ! the air con fired up and went cold.

    Stripped it all back down so I could make the wiring good, removed the scotch locks (there were 3 in all in one stretch of wire!) and soldered everything to make it secure and put it all back together.

    Air con now working. Happy boy
    Attached Images Attached Images
    PC gamer, steam ID maltloafs
    Xbox gamer, xbox live ID maltyuk

    i5 6600k @ 4.6GHz
    1660Ti OC
    16GB
    Lenovo Explorer VR
    Hyper X Alloy FPS keyboard
    LG Ultrawide IPS monitor
    Corsair Glaive mouse
    Corsair HS60 headset

    Xbox One S (mainly used for 4k bluray)
    Nintendo Switch

    2 Thanks given to maltloaf

    beansontoast (6th June 2015), Over Carl (6th June 2015) 


Similar Threads

  1. looking for mileage correction audi S3 2015 and audi Q3 2016
    By 949 in forum Digital Mileage Correction
    Replies: 14
    Last Post: 21st April 2017, 11:01 PM
  2. audi a3
    By smiglyy in forum Cars & Motorbikes
    Replies: 1
    Last Post: 30th December 2007, 10:08 AM
  3. Replies: 9
    Last Post: 26th July 2007, 06:44 PM
  4. Audi A4
    By super mike in forum Cars & Motorbikes
    Replies: 6
    Last Post: 18th July 2007, 03:32 PM
  5. Audi 80
    By Lee Macro in forum Cars & Motorbikes
    Replies: 4
    Last Post: 18th December 2006, 07:14 PM

Social Networking Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •