'92 Park Avenue

Got a problem that I'm hoping has an inexpensive solution. :) The automatic climate control on my '92 Park Avenue seems to have gone out. Whenever I press the 'Auto' button the climate control goes to 'Econ' instead. Everything else (heat, defog, dual, defrost) works fine, just the 'Auto'. I've checked the fuses so it's not that so has anyone ever had this happen before? If so, any ideas on how to fix it? Thanks in advance!

Should be low or no freon inside the system.
Check this: http://www.automotiveforums.com/vbulletin/showthread.php?t=265604


Mike