Drive over to AutoZone and they will run a free diagnostic check for you. The code that shows on their diagnostic machine will tell you why the error occurred, and what might be the cause. Sometimes the cause is simple like leaving off the gas cap, or a slight fault with an oxygen sensor. If you have no mechanical experience, you could ask a garage to fix a problem that, otherwise, might just be fixable at home. Ask them to clear the fault code for you; otherwise you will have to wait for 40 engine starts to clear the check engine-light.Good luck and drive safe... Dr Antony