A/C Codes - Need Help!
 

I've just purchased a 2000 CLK430 Cabriolet and the a/c doesn't blow cold. I've run the HVAC diagnostics and came up with the following values. Could someone please help diagnose my problem? The previous owner says the car needs an a/c sensor, but doesn't know which one.

Note: I do not have any DTC codes (the display read E FF).

These codes are for the various sensors I believe:

1 - 122
2 - 115
3 - 124
4 - 124
5 - 125
6 - 20
7 - 0
8 - 127

Does the 0 on sensor 7 indicate no R134a? Should I simply add a can or two and try again?

Please advise. I great appreciate any help!
M-

Check for pressure at the service fittings. If you have none, air may have entered the system. If there is pressure, you will be able to add refrigerant but you should locate the leak.