Do you recommend a coolant flush in my 2013 Hyundai Sonata with only 25,942 mi.?

What is your question?

Service manager recommended it; I took vehicle in because dash light for check engine malfunction light came on. The manager said that Hyundai doesn't recommend it at this time but they do. I bought this car in May, 2012 and have driven only 25,942 miles.

What makes this problem better or worse?

No symptoms regarding coolant.

How long has your 2013 Hyundai Sonata had this problem?

4 days