So, my A/C system quit working, no cold air, so I ran a Piwis diagnostics. Here is what I found:

1. Refrigerant pressure 2.4 bar, seems ok on low pressure side.
2. Compressor current 0A bad.
3. Compressor speed 0 RPM


so clearly, the compressor is not activated and may not getting the 100 hertz signal to engage.

I checked the two A/C fuses, which ohmed out fine. I am assuming since the ecu is reading the correct R134a pressure, it should enable the A/C relay?

Any advice in troubleshooting further? I know there are additional relays and fuses behind the rear seats, but I wasn’t able to find a schematic.

 

Good Rennlist threads on your issues. I just googled Porsche 991 A/C not blowing cold. It sounds like any refrigerant leaking (Low Pressure) from condensers might disable your compressor. I would start with adding some refrigerant and topping it off. See if that makes any difference.

AC Stopped Working

Porsche 991 A/C issue

 

Thanks, I saw that. I can’t find what the low/high pressures should be. Would you happen to know what they should be? 2.4 bar readings I go seems a little low.

 

I googled: Porsche 991 a/c refrigerant capacity

From Hard Rider: Thanks hard rider

You - 2.4 bar = 34 PSI
HardRider - When charging you want 35-45 psi at around 85F ambient.

Rennlist thread Below

A/C charge

 

Thanks!