Found this tool while browing on benzworld.
http://www.eclassbenz.com/acdiag

it's pretty cool, just enter in your error codes and sensor values and it gives an instant assessment and workarounds if there are any.

My response was as follows:

- Your 'EC' light must be off for the A/C to work. If the light will not shut off when you press the 'EC' button, this usually means one of three things: (1) You're low on refrigerant; (2) You have a defective refrigerant pressure sensor (usually caused by excess moisture in the system); or (3) You have a defective refrigerant temperature sensor.

- You have an error code for low refrigerant (Error code B1241).

- You should have the defective sensors replaced. But in the interrim, follow these instructions to override the sensor. (Your A/C compressor has its own pressure switch, so overriding the 'EC' light will not compromise this safeguard.) Switch the ignition on (position 2). Set the left temperature to 'HI' and the right temperature to 'LO'. Switch the ignition off. While holding the 'REST' button, switch the ignition on (position 2). On the left side, 'P1' will flash and on the right side, a code will be displayed. Press the 'EC' button twice so that the left side flashes 'P2'. Using the right side red temperature increase button, add 16 to the value. Press the 'EC button again to store the updated code. Turn the ignition off.

- Code B1226 Explanation: This sensor measures the temperature inside your car. It is reporting an implausible temperature. The sensor is located behind the small vent near your cabin light switches in front of the sunroof.

- Code B1227 Explanation: This sensor measures the temperature outside your car. It is reporting an implausible temperature.

- Code B1241 Explanation: You're low on refrigerant! Get your A/C recharged and this should go away. This code disables your A/C. You may be able to bypass this block if it's triggered by a defective sensor.

The trick to add 16 to the sensor measurement was particularly interesting. There were other posts in this forum that referred to this but didn't provide a link to the details. I made the change yesterday and will let you know how it fares after I test drive the car this weekend.