Audi D.I.Y. - A4 - Climate Control Head Unit Fix (B5)
10-31-2007, 02:00 AM
#1
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Audi D.I.Y. - A4 - Climate Control Head Unit Fix (B5)
Does your climate control head unit not seem to be doing anything? If you push the buttons, nothing happens? Or, you can see the display, but the backlighting is not working? This how-to will help you get things working again.
The fix for the inactive display is pretty invasive, so be warned. If you are not reasonably good at soldering on circut boards, find a friend who is.
This will apply to 1996 and possibly 1997 Audi A4, possibly A6 models.
Step one is to remove the radio. If you have an aftermarket radio, you should be able to just remove the trim plate, and unscrew the big wood trim plate. If you have the stock radio, you will NOT want to disconnect the harnesses unless you have the code handy. It is not really necessary to remove the harness anyway, as you should be able to slip the big trim over the radio and set it off to the side.
The fix for the inactive display is pretty invasive, so be warned. If you are not reasonably good at soldering on circut boards, find a friend who is.
This will apply to 1996 and possibly 1997 Audi A4, possibly A6 models.
Step one is to remove the radio. If you have an aftermarket radio, you should be able to just remove the trim plate, and unscrew the big wood trim plate. If you have the stock radio, you will NOT want to disconnect the harnesses unless you have the code handy. It is not really necessary to remove the harness anyway, as you should be able to slip the big trim over the radio and set it off to the side.
*NOTE* removing the stock radio requires special tools. You can get them at 'better' stereo shops, and at many VW/Audi Dealers. You insert them in the little slots in the radio, and pull the radio out using the tools as handles.
Once you get the trim off, you need to remove the CC head unit. There are 2 6mm Allens holding it in.
Once you get the trim off, you need to remove the CC head unit. There are 2 6mm Allens holding it in.
When you pull the CC head unit out, unclip the harness connectors (4 of them) from the back of the Head Unit. Keep in mind their order, though it would be pretty hard to get them back in the wrong order.
At this point, if you only have a burned out bulb, you can replace it (them). As you can see in this image, the 4 colored screw looking things are the bulbs. Use a flat tip screwdriver to remove the offending bulb. The inner 2 are for the display lighting, the outer 2 are for the lighting when the dash lights are switched on.
If you have an inactive panel, you will need to take out the 3 screws from the back. You can see the top 2 screws in the above picture, and there is a 3rd on the other side. Once the screws are out, you can pull the face off. It's a good idea to hold it with the bottom up, so you can unclip the ribbon cable from the face. Use extreme care here, you don't want to break things worse than they already are.
Now comes the hard part. There are 4 tabs on the bottom, and 2 tabs on the top. It is VERY important when you are pulling the face off to keep the buttons facing DOWN. Once you get the board free of the front panel, the buttons and light conduits will be free to fall out all over the place. You have been warned. Luckily it's not too hard to get it all back together if you do happen to tip the face plate the wrong way
Now comes the moment of truth. You have the circut board free, and you can re-solder the ribbon cable socket. In the image I circled the points you will want to re-solder. Use care here. Its a good idea to check for continuity on all of the various contacts throughout the board. Use a multimeter set on continuity check, and check between the contacts for the switches, and the ribbon cable studs. (NOTE, in the picture, I pointed to 2 contacts, there are more than 2, obviously. Under each of the little rubber buttons is a contact.)
08-11-2008, 08:00 AM
#2
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Join Date: Aug 2008
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Re: Audi D.I.Y. - A4 - Climate Control Head Unit Fix (B5)
This is really excellent - thanks Boosted A4.
I think you've missed a small step though. Once you've freed the face, the display is covering the points that need soldering.
You next need to remove the display - which is very easy, simply twist the 8 tabs on the back so they are flat and the display lifts off.
I tried to put two photos in the right places that I took showing display and removal, but I failed!
I hope I've managed to attach them. Perhaps a kind moderator will put them in the right places for me...
Loz
I think you've missed a small step though. Once you've freed the face, the display is covering the points that need soldering.
You next need to remove the display - which is very easy, simply twist the 8 tabs on the back so they are flat and the display lifts off.
I tried to put two photos in the right places that I took showing display and removal, but I failed!
I hope I've managed to attach them. Perhaps a kind moderator will put them in the right places for me...
Loz
01-09-2009, 11:37 AM
#3
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Join Date: Jan 2009
Location: Calgary
Posts: 4
Re: Audi D.I.Y. - A4 - Climate Control Head Unit Fix (B5)
anybody know how to get the readout from Fahrenheit to Celsius?? I bought my 98 A4 down in Phoenix, and it's in F. I need celsius, and after talking to Glenmore Audi, they told me that its just a sequence of buttons i need to push.
Anybody know that sequence?
Anybody know that sequence?
02-15-2009, 03:04 PM
#4
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Location: Mason, Ohio
Posts: 2
Re: Audi D.I.Y. - A4 - Climate Control Head Unit Fix (B5)
Anyone know where the Temperature Regulator Flap is located? I have a 1996 A4, blows strong, heat getting into and out of core, flushed, both hoses get hot. The only error message I get on the control unit is 8.7 - Temperature Regulator Flap, sporadic block. Suggestions?
Thanks.
Thanks.
02-15-2009, 03:56 PM
#5
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Join Date: Oct 2007
Location: Schomberg, ON
Posts: 100
Re: Audi D.I.Y. - A4 - Climate Control Head Unit Fix (B5)
You can change the climate control to be in Fahrenheit or Celsius degrees. To switch, press the recirculation button and hold, at the same time, press the temperature "+" button.
02-15-2009, 06:02 PM
#6
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Join Date: Feb 2009
Location: Mason, Ohio
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Re: Audi D.I.Y. - A4 - Climate Control Head Unit Fix (B5)
Anyone know where the Temperature Regulator Flap is located? I have a 1996 A4, blows strong, heat getting into and out of core, flushed, both hoses get hot. The only error message I get on the control unit is 8.7 - Temperature Regulator Flap, sporadic block. Suggestions?
Thanks.
Thanks.
05-24-2009, 08:24 PM
#7
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Join Date: May 2009
Location: Ohio
Posts: 1
Re: Audi D.I.Y. - A4 - Climate Control Head Unit Fix (B5)
the info on this site has been great. any suggestions for flickering lights on the climate control? the lights for the center of the control(shows set temp and fan speed) will come on sometime or just flicker. i used to be able to flick it with my finger or tap and it would come back on for a bit. i did the procedure to get it all apart but i don't see anything visibly wrong. is it possible that one of the 4 bulbs isn't working right? confused. any help would be appreciated. thanks!
10-25-2009, 01:25 AM
#8
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Join Date: Mar 2007
Posts: 98
Re: Audi D.I.Y. - A4 - Climate Control Head Unit Fix (B5)
the info on this site has been great. any suggestions for flickering lights on the climate control? the lights for the center of the control(shows set temp and fan speed) will come on sometime or just flicker. i used to be able to flick it with my finger or tap and it would come back on for a bit. i did the procedure to get it all apart but i don't see anything visibly wrong. is it possible that one of the 4 bulbs isn't working right? confused. any help would be appreciated. thanks!
Any input appreciated.
06-21-2014, 09:14 AM
#9
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Join Date: Jun 2014
Location: Malta
Posts: 1
Re: Audi D.I.Y. - A4 - Climate Control Head Unit Fix (B5)
This is a very important mail, thanks. The pins of the plug which is soldered to the display board which you access after removing the display is the source of almost all issues which arise. In one case, all worked well except lights went off. Ok 1 bulb out of four had to be replaced but the other three were good. The fault was two dry joints on two of the pins (inside that blue circle) on the PCB which were also easily visible as being completely dry. I soldered the two connections, the lighs went on! On another occasion, the AC and fan just would not work. I sucked all the solder out with a gun on all of these pins of this plug. I soldered all the pins again and voila. It worked perfect. Yes, learn this from my experience. The electronics rarely ever fail. Most problems are caused by dry joints, switches especially the tiny once which are surface mounted and on this panel and on car radios too, male and female sockets......these account for the majority of problems. So doing and chekcing the basics resolves loads of problems really.
07-27-2015, 01:57 AM
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Join Date: Jul 2015
Location: Australia
Posts: 1
Re: Audi D.I.Y. - A4 - Climate Control Head Unit Fix (B5)
This post was very useful. In fact I used these instructions to fix my display on the climate control. I have done a quick video on this as well. Here is the link in case any one needs it for reference.
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