On my 96 C280, the sequence to reset the climate control module is as follows: Set the temp to "LO". Turn off the ignition. While holding the "REST" button, turn on the ignition(do not start the engine). Release the "REST" button. "00P" will appear in the display. At this point you can push the fresh air button to cycle through 15 codes. To exit, push the "EC" button. Start the car normally. I don't know what the different codes do. I use the default 00P and it seems to do the trick. If this doesn't work you could try setting one of the other codes. I learned this trick because every 1 or 2 weeks my "EC" light comes on shutting down my A/C. Resetting brings it back. I think it is a problem with the evaporator temp sensor which I'll deal with someday. Good Luck,

Dan