Check Engine light at 36000 miles
 

My '04 Sonata hit 36,000 miles today, and when it did, my Check Engine
light came on (Not sure if it was exactly at 36000) When I noticed the
light, I had 36,003 miles.

Is this normal and will it go out on it's own, or is this yet another
trip to the Hyundai dealer, and if I do need to go to the dealer, is
it something that is covered under warranty?