WARNING: This page is about a different car, the 2012 Hyundai Veloster. However, it is still accessible from the selected car via links, so may be relevant.
Fig 1: AVN Remote Control Schematic
Courtesy of HYUN
Fig 2: AVN Remote Control - Circuit Diagram (Audio And Cruise)
Courtesy of HYUN
Fig 3: AVN Remote Control - Circuit Diagram (Bluetooth And Voice)