Why is my A/C only blowing warm or hot air?

Hi, Did you find teh answer to your A/C problem. I have a 2002 E320 and it has 10,755 miles on the odometer. I don't drive the car too often. I decided to drive the car today and turned the air-conditioning on and put in on automatic climate control. Just noticed that the air is blowing out cold from the passenger side vents but blowing out warn from Driver's side vents. I even tried the Manuel mode instead of climate control but same problem. I put my question at teh Mercedes Benz website form and I received this answers: The warm air on the drivers side often indicates low A/C refrigerant. There is a useful test you can perform that will aid in diagnosis. On your climate control console, press and hold the REST button until the display changes to a 1 on the left and another number on the right (10 seconds or so). This places the HVAC system into a diagnotic mode. Pressing the left side Auto button will change the left side channel 1,2,3,..etc. Run through the channels and record the right side numbers and post them here. When you run the test make sure the engine has been running for 5 minutes or so and keep it running during the test. When you are done press the REST button to restore the usual display or turn the car off. Here's what the different channels represent and sample numbers: 1 (Inside Temp): 82 2 (Outside Temp): 76 3 (Left Heater Core Temp): 82 and later 114 4 (Right Heater Core Temp): 84 and later 107 5 (Evaporator Temp): 80 6 (Engine Coolant Temp): 186 7 (Refrigerant Pressure): 04 8 (Refrigerant Temp): 91 9 (irrelevant) 10 (Blower Control Voltage) 6.0V 11 (Emission Sensor) 2.4V 12 Sun Sensor: 4.1V 20 Control Current for Auxiliary Fan: 3.2mA (Is this value too low?) 21 Engine Speed: 44 or 4,400rpm 22 Vehicle Speed: 0 (makes sense to me) 23 Terminal 58d: 32 or 32% 24 Battery Voltage: 13.3V 40 Software Status: 164 41 Hardware Status: 85 42 ???: 40 43 ???: 136 After I did the test, my results were as follows: 1 (Inside Temp): 91 2(Outside Temp): 96 3 (Left Heater Core Temp) 91 4(Right Heater Core Temp) 87 5(Evaporator Temp): 91 6(Engine Coolant Temp): 190 later 191 7(Refrigerant Pressure) 06 8( Refrigerant Temp) 107 later 111 9(irrelevant): 27 10(Blower Control Voltage) 4.5 11(Emission Sensor) 1.7 12(Sun Sensor) 4.3 20(Control Current For Auxiliary Fan: 3.2 21 (Engine Speed): 42 22(Vehicle Speed): 00 23(Terminal): 32 24(Battery Voltage) 13.1 40(Software Status) 164 41(Hardware Status) 91 42(???): 40 43( ???): 136 Then I received few replies from other MB owners in the form and they wrote as follows: If one side is ice cold and one side is warm, most likely is a sticky duovalve. Enter diagnose mode and post values. Just a tip, if one side sticks open and warm air blows one side, press front windscreen defrost for 5-10 seconds and release after. This might help to move plunger inside duovalve all the way and then to return to normal. Another one wrote from Canada: Your refrigerant is low. Pressure as measured on item 7 should be about 15. Freon is a very "slippery" fluid and is difficult to contain. It's not uncommon for MBs to develop leaks after 9 or 10 years. You will need to have shop check out your system. They will likely evacuate it and then recharge with proper amount of R134a along with a dye. After driving for a week or two, they will be able to inspect and determine where the leak is. I know from experience that it is frustrating to have expensive A/C repairs when the car is little used and A/C seldom needed. Some owners will try a temporary solution. Walmart sell R134a and recharging kits. It's easy to do and the A/C may work for a while. But not a long term solution. And then the original owner who told me to do the test wrote me back as: I agree with MBGraham. The duo-valves may require cleaning as well (channels 3 & 4). FWIW, with a similar outside temp my 3 & 4 report 48 degrees. So if you find the answer, please email me . Thanks !