audia6s

It was so hot in DC today that I decided to turn on my AC for the first time in several months. I soon found out that no cold air was coming form the vents. Ran diagnostics and got the following code:
Address 08: Auto HVAC Labels: 4F0-910-043.lbl
Part No SW: 4F0 910 043 A HW: 4F1 820 043 AG
Component: KLIMABETAETIGUNGH30 0020
Revision: 00000053 Serial number: 00000030288631
Coding: 0524326
Shop #: WSC 02325 758 00200
VCID: 1C3DA5D4DFB0D8E

1 Fault Found:
00256 - A/C Pressure/Temperature Sensor (G395)
002 - Lower Limit Exceeded - Intermittent
Freeze Frame:
Fault Status: 00100010
Fault Priority: 3
Fault Frequency: 20
Reset counter: 76
Mileage: 100744 km
Time Indication: 0
Date: 2013.01.30
Time: 21:10:40

Before I order, could anyone confirm that this is the right sensor:

http://genuineaudiparts.com/parts/20...SSURE%20SENSOR

or may be a way to get the old sensor working?

Thanks in advance.

eazy211187

It looks like that's it, but sent Bill an email. Have you try cleaning the sensor connection?

Also something new I learn a few weeks ago.

An A/C tech told to run the A/C for 30 sec to 1 minute at least once a week. So the freon could flow there the system and also the oil could lubricate the bearing in the compressor and valves.
That's to avoid a/c break down that could run you up 1k for stuck bearing valve. Yes even in the winter weather.

Also for those of you that recharge your own vehicles, he doesn't recommend the freon with the leak seal additive. Additive costs more problems in the long run.
But if you go on road trip in extreme heat and the a/c stop cooling, to go for it. Just make sure you have your system check once your back home.

Nice ride, you should white vinyl wrap the bumper markers.

audia6s

Eazy,

Could you provide me with any info on where to find the sensor or how to replace it? Also, if I was to replace it, will I lose the freon and will have to re-fill the AC again? Thanks

eazy211187

Well the ac pressure sensor is next to the left headlamp, behind grille. You'll have to remove the front bumper to have better working space. But some people have luck with undoing the top portion of the bumper squeezing there hands through. But your better off removing the bumper.

Here's a link the where the sensor at. Just zoom in in the image. The sensor is #5 but you should also get round seal #3 and valve safety switch #4. But that up to you.

http://www.jimellisaudiparts.com/sho...ssembly=746720

As for the freon, I won't be able to tell you. But if you have everything prep just swap them fast. You should good.
Just in case you could away buy a bottle of freon R134A.

newa6er

If you remove the pressure sensor and all the pressure leaves the system then you must vacuum the system before adding Freon.

audia6s

Thanks for help guys. So after digging through OnDemand5, I found that the Audi is aware of my issue have issued TSB as of 2010 (attached). I have never done AC work so these past few days, I am trying to educate myself before I start on this DYI. I was quoted $320 for this job so I rather do it myself. I also want to flush the refrigerant, but little confused on the process. From my understanding, I need to drain old freon out, vacuum the system to ~27mmHg, then add new freon. I am pretty comfortable with step 2 and 3 (after some research). The only thing I don't understand is how to, and what is the process, to get the old freon out for proper disposal. Any thoughts?

audia6s

So the sensor came in today. Got the instructions on how to take front bumper off, get to the sensor. Can anyone suggest what should be done with freon prior? Do I need to drain it before taking the sensor off? i don't want something to blow up in my face

newa6er

you should take it to a shop so they can capture the gas

audia6s

So what you saying is I need to pump the freon out first before replacing the sensor and then to refill the AC again?

xtreetoes

First your car doesn't have Freon, no car since 92 has it. You have R134a. When I was in the 10th grade I worked in a shop installing AC in cars that didn't have them.

Unless you have a vacuum pump and the pressure gauges I recommend taking it someplace to have the work done. If it were me I'd pay the 325.00 and be done with it. By the time you buy R134a, the gauges, and getting a vacuum pump you will be almost there in cost. Not worth it for a onetime job IMHO.