Thread: How to test air con with VCDS?

My air con / climate stopped blowing cold air so i got it regassed and dye put in, it worked for a few weeks then stopped again. Found a pin hole in the condenser thanks to the dye replaced it and regassed all ok again. Couple of months gone by and no cold air again, went for a regas but basically what came out was the correct amount so no leak this time. I've scanned with VCDS and got some codes which i had a few years ago when i bought the car.
3 Faults Found:
01810 - Actuating Motor for Temperature Flap; Right (V159)
41-10 - Blocked or No Voltage - Intermittent
00716 - Air recirculation Flap Positioning Motor (V113)
41-00 - Blocked or No Voltage
00735 - Potentiometer in Positioning Motor for Air recirculation Flap (G143)
30-10 - Open or Short to Plus - Intermittent

At the time i just cleared them as the air was working fine and a member on here has had the same codes after a flat battery and not using the climate for a while. I've been playing with VCDS and all the above motors are working and are within spec according to VCDS. I have cleared the codes and they have not retuned 2 days so far.

Is there anyway of knowing what readings i should be getting from the compressor in pressure terms as the only one i can find in measuring blocks is running at 8 bar rising to 10 bar after a few minutes, is this correct? the compressor is the type without the magnetic clutch and appears to be working as i'm getting a torque loss reading when it switches on.

The cooling fan does kick in when the air con is on and i've checked all the fuses in the side fuse box and the hidden ones above the steering column / dash panel

I was hoping for a faulty pressure sensor or at least some code relating to the hvac unit but i'm not so lucky.

I have access to a Bosch air con machine but the owner only uses it for regassing so hasn't got a clue about diagnosing faults other than leaks. (what a waste of a machine and loss of possible income)
The car is a 2002 A4 diesel quattro se not the car in my signiture.

When you had the condensor changed, did you renew the receiver/drier too? Renewing a part of the system without putting a new R/D in is like fitting new brake discs and putting the old pads back in

If you haven't had a new R/D, thats the first thing I'd change and get the system vacuumed down for at least an hour to remove all crap and moisture. If that doesn'nt solve it then it could be the expansion valve at fault. The expansion valve is the last component before the refrigerant gets to your evaporator inside the car, and its the EV that drops the temperature of the refrigerant to brrrrrr!

Other vthan that, it's one of them jobs that I really need to see the car to be definite

A little update, after further investigation the newish air con condenser is leaking slightly, luckily it's under warranty so will be replaced along with the drier shortly. I'll post back if it still doesn't work.

New condenser and receiver fitted and all is cool at last.