I also found this from Hyundai website (I am NO mechanic..):

HEADLIGHTS OPERATE NORMALLY, BUT DRL SYSTEM IS INOPERATIVE (LIGHTS
NEVER TURN "ON")
Blown fuse
Open circuit in wiring harness
Defective generator
Short to ground in brake warning indicator circuit
Defective park brake switch
Defective brake fluid level switch
Defective DRL unit
.-....

I have checked the fuses, all seem ok.
Open circuit in wiring = I dont know what it is
Defective generator = what is this? the lights work normally if I
manually turn them on..
Short to ground in brake warning indicator circuit = dont know, but all
other lights work..
Defective park brake switch = dont know?
defective brake fluid level switch = dont know?
Defective DRL unit = most probably, where do I find this one??

...

Thanks,
Øystein