why would the engine light come on but the car runs great? on 2005 Cadillac Escalade

engine light just came on

Asked by for the 2005 Cadillac Escalade
2 answers
Check this article in the Repairpal's Auto Repair Encyclopedia; http://repairpal.com/check-engine-light
Fuel cap could be loose. Tighten cap and drive for a day or two to see if light goes off.