The symptoms: A/C is blowing, but not cooling. Compressor clutch engages. Low pressure line refrigerant pressure ~30psi (2.1bar) -- supposedly "normal" -- measured w/gauge.
After searching the threads on A/C, and reading the codes, the only thing wrong I could notice was code 7 (compr. press.) parameter, having range of 4.8 to 5.3 bar.

Any ideas of what the most likely scenario is? Any other diags I could run?

Any advise is much appreciated.

Is it stuck in the Economy mode?

Len

UPDATE: Added R134 anyway... and fixed the problem. Apparently, low side's pressure was not that significant: after adding freon, low side pressure stayed at ~ 30psi, while high side immediately jumped up (to over 10 bar), and cold air started blowing.

Thanks to all.

You might want to have the system checked for a leak(s).

__________________
John Shellenberg
1998 C230 "Black Betty" 240K

http://img31.exs.cx/img31/4050/tophat6.gif

Knowing the low side pressure alone, is not nearly enough information for diagnosing or even charging an a/c system.

I'm glad you're cool again,

This car has a variable displacement compressor. Instead of cycling on and off to control the evaporator temperature, it just changes displacement. So the low side is always going to read ~30PSI. You have a freon leak somewhere. Don't forget to add PAG oil, as you're losing that too.

- JimY