security light on

Chances are pretty good that you will need a new ignition lock cylinder. RepairPal has an article on GM passlock systems that can provide more information. Confirming the fault with the security light on your 2001 Chevrolet Lumina through proper diagnoses should be done before any repairs are made. Here is the link to the article: http://repairpal.com/gm-passlock-security-light-issues.