Christian Bungur

Hello, I am new to the forum. Having problems with the climate control. The car is an A4B5 1995 year. The original climate control died on me half a year ago, so I opened it up seeing that it has been resoldered before, tried to repair got nothing. Bought a new one same number and it worked great for about 3 months and the screen died, opened it up and of course it has been repaired, tried to repair it again with no success. Bought another one this time from a 1999 car (black plastic) since there was no white one on the market. Today I tried to turn the ac on and the compressor did not want to start. Does anyone know if there is a difference between the two models of climate control software or wiring?

desertsage

Hello Christian! I've learned that the A4 climate control modules are very specific between model years, as in: a module from a 1996 will not work in a 1997. It is also possible that your AC issue is caused by something else. A scan will give you a better idea if the climate module is actually at fault here. The AC system will also not start up if the refrigerant pressure is too low, as in a leak. If the outside air temperature is too low the AC system will not start, as a protection.

In the US, Module Master does a great job of repairing these and their work is guaranteed. They repaired and tested the climate control module for my '96 A4, replaced the LCD screen and the illumination lamps for $100. https://modulemaster.com/

4Driver4

Desert is correct. Lots of differences in those units.
IIRC, 1993/1994 Audi 90 is the same as those early A4 cars. You should post your location and part number of your original unit.

Christian Bungur

The original unit has codes 5HB 006 500-11 and 8D0 820 043 H. I didn't take a picture of the new one, unfortunately. The car is at the end of its life maybe got 2 years still in it 400 000 km as far as I know, worth max 1000$ so I doubt I will be sending the controller for reparation. Gona hook the car up to a diagnostic these days, maybe it yields some results.

desertsage

Hey Christian, There are many of us here who are all about keeping our old Audis on the road. They are very much worth it. The B5s are slowly moving into the "classic" category. You'll be happy that you had kept it going. I'm hoping that you don't give up on it.

Christian Bungur

Of course, I haven't given up on it. It has been serving me faithfully since 2017. Went on a lot of vacations to other countries with it. But the engine could use a tune-up it does smoke, drinks 1,5-2l oil per year, the turbine has some play in it, HVAC is in bad shape ac was slowly failing even before the new climate control, heating is not the best since the foam from the heating flap blew ou the vents,... The car in general is not worth restoring. I will probably keep it until it starts falling apart
But I admire the efforts of people trying to keep them in good shape on the road, unfortunately here they are mostly a reliable workhorse noting more. Same as the audi 80's b3/4 until maybe 5 years ago, now you can really see one on the road.

Christian Bungur

Hooked the car to a diagnostic tool and it got 5 fault codes on HVAC module:
01274 Stepper motor road speed damper blocked or no voltage (permanent)
00792 Pressure switch climate control system short circuit to ground or open circuit (permanent)
01297 Temperature sensor inlet air floor short circuit to positive or open circuit (permanent)
01206 Time signal ignition off faulty signal (intermittent)
01582 Engine coolant temperature signal short circuit to positive or open circuit (permanent)

Controll unit indentification code is 8L0820043D A3 klimavoll Version: D75 Controller varriant: 03140 WSC code: 06313

After deleting the faults, starting the car up and trying to use HVAC the following faults returned: 01274, 00792, 01297, 01206, 01582, so all of them. Before when I hooked the car up to diagnostic it would only show the first fault (stepper motor)

desertsage

If these codes came up for me, I would replace the coolant temperature sensor, clear the codes again and see what remains. A faulty coolant temp sensor could cause other issues downstream, from my experience.

I'm not experienced enough with the HVAC system to know whether any of the other codes could be caused by an incompatible climate control module. Maybe 4Driver4 could shed some light on this?

Victorymike18

I am fortunate that the HVAC on my '97 A4 seems to work well-enough. However, I have wondered if there would ever be value or interest in reverse-engineering the system and creating a replacement that makes it a simple three-dial system? Probably not a worthwhile endeavor, but I personally don't mind stuff like that to be manually controlled.

Christian Bungur

Problem solved, took the 2 dead climate controls and made 1 working one. Now it displays digits and all the functions work.