A/C quit.....2001 e320 Wagon. 4 matic. amongst other things !

[dkveuro]

Customers 60,000 mile wagon has a freon leak and was pressurised by MB of OKC last autumn.
The EC symbol 'red' lamp is on when commanding a/c.
Snap On scanner Mercedes cartridge does not communicate with
a/c, but it does read a/c command request which reads OFF.
I found system had 25 psi static pressure and added to 85 psi from 30 lb bottle but still no a/c function. Also noted the FAN will occationally change speeds slowly and erratically and sometimes go from slow to med and back again with no input , display does not change during this system quirk.
She tells me MB of OKC also installed a new push button facia module last year for same problem.

Futher more I recorded many engine P codes as CHECK lamp was lit. They where as follows in order listed.....
P2085 Part Load Fuel Trim Bank 2 limit.
P2016 Ditto, Bank 2.
P2017 Idle Fuel Trim Bank 1 Limit.
P2086 Ditto Bank 2.
P203E No/Incorrectmessage from I C.
END.
I cleared codes and none returned on teat drive of 5 miles.
I did notice post cat bank 2 O2S was not ranging but staying at 0.71 while Bank 1 ranges from 0.002 up to 1.096. which seems O2S 's are begining to fail. Post cat sensors ranged okay only after holding rpm's to 3000 for 2 minutes.
Noticed that adverage fuel milage was recorded at 14.6 mpg on test drive. Seems a little low to me. She says usual mpg is 20 plus.

Seems I might be quoting her for O2s , what is your take on all this ?