I have a 2007 s6 with 81,000+ that I’ve have for a few months. I found that it had a refrigerant leak so I charged it with one of the 134a,dye and sealer products and it seemed to correct my issue. After a few weeks of working great it stopped on the hottest day so far this year. System pressure is good and it seems like the compressor isn’t coming on. I have vagcom but Im new to it so I’m not really sure how to best use it to troubleshoot the ac system. Based on what I’ve read online the pressure temp switch is both a common leak and fail point in the system. Before I take the car apart to check it with a meter can someone point me in a direction to check it with vagcom or a good troubleshooting guide for our cars? I bought a service manual online but it’s really more of a how to replace things you have already diagnosed. All the diagnostics it list are to use the Audi dealership scan tool and replace whatever it tells you to, not really helpful.
Currently I have no trouble codes when I run a scan. When I look in module 8 I can see the electric fans are on due to a call for ac and the static pressure of the system is well within the normal range but the compressor is listed no load and a voltage around .6 something. I thought I read somewhere this is the reading you will get when the compressor isn’t running and 12 v when it is. I also read the pressure/temp switch if bad will prevent the compressor from running. Again any help would be greatly appreciated.