My 01 Cavalier's service light went on and I found that my passenger headlight on low beam was burned out. So a burned out headlight will cause your Cavalier to emit the service light. I saved money by checking my headlights so for those reading this now, do check all your lights on the Cavaliers.
That light means you have an electrical problem you have to check the electrical wiring, you just can't turn it off manually. I have a Chevy Cavalier 2000 and it flickers when I put it in drive and then it stays on