The automatic transmission needs to receive a signal from the brake light switch to operate the shift lock solenoid. Check to see te brake lights work, check fuses
SENSR 2 (10 Amp) in engine compartment fuse box, and check STOP FUSE (15AMP) in the fuse box behind the dash. Hyundai as a car manufacturer put a lot of free technical information and workshop manuals on line for Hyundai owners. Check out www.hmaservice.com lots of great information.