2009 Caravan ,MIL is on now, don't know why.. just changed engine oil and rear break paddle and filled #87 fuel 3 days ago??
thanks

 

Take it in to any auto parts store that offers a free check engine light check. Write the code(s) down - they should begin with a letter like P, B, or C, followed by 4 digits. Then Google that code or do a search on this website.