Pchelka01

to start off these are the non erasable codes that i keep getting


Saturday,12,May,2012,11:20:57:36210
VCDS Version: Release 11.11.2

Address 08: Auto HVAC Labels: 4B0-820-043-MY2.lbl
Control Module Part Number: 4B0 820 043 AD
Component and/or Version: A6-Klimavollautomat 0104
Software Coding: 00010
Work Shop Code: WSC 02325
VCID: 5CA95C81CC30A63
2 Faults Found:

00779 - Outside Air Temp Sensor (G17)
30-00 - Open or Short to Plus
00819 - High Pressure Sensor (G65)
30-00 - Open or Short to Plus


The econ button is always on when i turn on the climate control,
i have bought and changed both sensors, and it is still on, and still cannot erase these codes. Kinda lost now, need some advice!


When i first bought the car i ordered a preowned climate control from a 2001, due to the buttons on mine being really scratched. So when i got this one, i saw the different part numbers so i decided just to switch the face from the one i bought to my old own. I had no complications doing so, (although there was one extra connecting wire which i did not connect, due to all of the other wires were exactly like mine.) Could this have anything to do with it?

the climate control seems to be working fine, i have checked every feature on it and it was fine.

Please help!

ezveedub

Did you have these faults before swapping the HVAC controls? A 2001 Allroad HVAC control head will not work properly in a 2002 and up Allroad.
The DTC's you have are not for bad sensors. The DTC's codes mean you have no ground to the sensors.

Pchelka01

That is what i cannot understand, i switched only the face of the unit, meaning the front panel and buttons, everything else stayed, so it is my old unit just with new buttons. that is why i didn't think this was the problem, what else should i look at?, checked the fuses driver's side.

Sgt G

I'm wondering if the inner workings of original climate control head unit are the cause requiring replacement again? The front facia is new, insides are still original. I've read here on other threads that when Econ button sticks on, it can sometimes be climate control unit as causal. You may need entire unit this time.

Pchelka01

I just came to a junk yard a took a climate control unit from a 2004 a6, the part number was the same except the last letter instead of AD it was AR , I did a scan and the same codes come up!! Where should I look next??i hav not checked for relays, could that be the problem? Which relay should I check?

Pchelka01

anyone know what relay it is for the a/c?

Pchelka01

so i had some time to look into my ac issue, and here is was what i got,

Econ on the climate control is on, showing 2 codes that i mentioned before, Condenser and both fans do not turn on (passenger side fan and the one in front the condenser, If i wire the fans directly to the battery they turn on, check all the connections and wiring in the front and out of the climate control, also checked all fuses, (checked fuses, but do not know for sure how to check them or which one),
Went to an a/c shop and they vacuumed everything and than put oil, dye and Freon to spec. still no luck

i'm kinda running out of options any help would be appreciated! Still am thinking that it is my climate control, the previous one i checked was from a different year (2004) and a different last letter of the part number. guess i might need to buy another one.

Prospeeder

Baiscly take a multimeter, check that both wires to and from those sensors at the control head have continuity. If they do, the climate module is junk

Pchelka01

To both the high pressure switch and the outside temp sensor as they both lead into one connector near the power steering reservoir, Idk why but the wires fried together from the engine heat, so I want to rewire the entire connector and all the sensors it goes to so I'm looking for a wiring diagram

Pchelka01

No one has a wiring diagram?? I have the Bentley manual for a bunch of Vw and for the a4 and a8 but not the a6 or allroad, was wondering if someone could save me some stress and post a wiring diagram to and from the pressure switch I would deeply appreciate it,
Thanks