Would a tune up resolve the "check engine" light problem? on 1994 Suzuki Swift

Check engine light came on when driving to work. Stayed on when driving home. I could not detect any other problems.

Asked by for the 1994 Suzuki Swift
Not likely....need to scan on board computer to see cause of malfuntion.
Thanks for your reply, I appreciate your help. It helps to have a second opinion. I was told that it might be that the gas cap might be loose. I have a gas cap that locks. I looked at it, cleaned it & twisted it back on. The check engine light seems to be dimmer. What do you think?
Its either on or off. If the cap was not loose you probaly still got a problem. Some of the chain operated parts stores will hook up to your car a get the fault code for you. If you can get that code and get back to me I will see if I can help you more.
Thanks again for your reply. I will try to get the info you requested.