I am a former E-class owner who made frequent use of the climate control diagnostics on that auto. I am thinking of buying a 2004 C320 and am wondering if that vehicle has similar diagnostics.

 

If it has option 581 fitted completely, you will get complete use. Easiest way is to check for charcoal filter button assuming it has full dual climate control with digital display.

to ensure it hasn’t just been face swapped, you can peek under the glovebox for the actual filter.

some, like me, upgraded to the display and only updated/added the solar and smog sensor additions.