I, too, have an '03 and have had the "malfunction light" come on 3 times now. first time was because I was an idiot and didn't secure ("click") my gas cap. other 2 times were when my Jeep did its spittin' and sputterin' thing (still haven't figured out why). anyway, if you turn your key on and off (start postition) 3 times and then leave it on, some codes will appear on your odometer (mine told me that number 3 cylinder was missing, and I though "no s#*t, tell me something I don't know!). the manual says it'll go off sometime during the next 40 starts, or some such s#*t, and mine did eventually go off (and she returned to running as she should!). I'm thinking that if she's running fine, and your gas cap's snug (clicked in), give it several start cycles to see if it goes off and, if not, guess you gotta take her in to the dealer. Sorry!