2001 C240 EC Light Stays On
 

I cannot get it to turn off, and of course the air conditioner compressor will not turn on while in EC mode. I tried replacing the temp sensor under the dash, but the EC light still is lit. Pushing the button has no effect.

Help...It's gettin' hot in here...

Check for codes in the automatic climate-control pushbutton unit. Also check for presence of refridgerant.

How do I check the codes?

I checked refrigerant last night. There seems to be plenty according to the gauges.