Hi Mary,

Well, the 2010-2012 Santa Fe 2.0 diesel has a timing chain, so no maintenance needed there, generally speaking. The 2.2 diesel of the same generation has a timing belt though (well, the 150hp one does... the 197hp one has a chain), and that needs to be changed every 160,000km or 10 years. 

If it's the current model you have, which is from 2012, then it has a timing chain.