99 E320 wagon Climate Control stays on economy mode EC and does not allow air conditioning kick in even if you lower temperature setting to lowest How do you get out of EC mode?

EC mode typically kicks in if you are low on freon or have a defective sensor(there is a self diagnostic program that can tell you which error codes are present that I found in the benzworld online forum), I have the same problem and have had the freon recharged, but it must be a defective sensor, there are a few of them.