2006 Other Hyundai Models check engine light

My azera was bought new and within the last 5 months the check engine light has come on and each time I called the dealer to make an appt. (Within 2 days) the light has gone out before the dealer could check it out. I t came on again last night and this morning it went out by itself again. Do you have any idea what could be causing this.
Except for one time when the car ran rough (and then ran well after I shut it off and restarted even though the light was still on) it has been running fine. It's a problem running to the dealer every time the check light engine goes on. Other than that, I love the car-it's a gem
Thank You