2001 c320 with Climatronic
I was trying to turn on my rear window defroster (while driving) and pushed the "economy" button by mistake. I held it down a little longer than needed and I think I went into a diagnostic mode. I let go of the button and pressed it again. The Economy light is on and won't turn off. I have pressed it several times. Still on. Disconnected my battery (hoping it would reset) for 30 min., still on when reconnected. Removed Climatronic unit (again hoping it would reset) still on. Since it is stuck in "economy" mode the compressor won't come on.
Any ideas? I need my A/C again. Is it the Climatronic unit or is there another item that may need replacement?
Any help would be great!
Thanks

update: I don't think the "economy button" is the problem because if I press and hold it down then it goes into the diagnostics, then I press it again and it goes out of the diagnostics. Would that mean the button is operating properly?

 

Most of the time when the EC light remains on all the time, there is something either wrong with the A/c system or there is some sort of stored fault code in the control module. It is also possible that the refrigerant level is low due to a leak which will cause this light to come on also. I would check around the receiver/drier and see if you are leaking anything.

 

Thanks for the hints. No leak anywhere. Anyone know how to clear any stored fault codes in the control unit?