Same issue with 2012
 

Any other ideas on the issue? I have a 2012 with air bag light on, no horn, and no cruise control. But radio controls and phone controls, on left side of steering wheel, work. Cruise control and trip computer buttons , on right side, do not work. Ive tried spinning wheel i all directions to see if horn would work but nothing.

Sounds like possible clock spring issue

What someone will need to do is , check if power or ground are getting to the horn pad and go from there. It all does go through the clock spring in the steering column and is not a job for the usual DIY person ,,,,because ,if you do not know what you are dealing with you could have a discharged air bag in your lap.
As anyone can tell you that has one go off, it sounds like a shotgun when it goes off. Smart move to leave the complicated work to the pros.

Sorry for commenting 2 years later, but did you figure out a fix for this? I'm having this exact problem...same buttons do/do not work as you described. Same model, same year.

If you had to take it into Hyundai for a fix, approximately how much did that run? I just spent $900 to fix my AC blower through Hyundai, and I feel like a chump.