Welcome Kymco Owners!
I can't find a 5 code. On my DT it starts with 6 and indicates throttle position censer fault. If it was a one time thing you should be able to clear it. Put the bike on center stand, side stand up, kill switch in run, turn on ignition. After 10 seconds turn throttle to full for 10 seconds then release. after 5 seconds light should blink twice half second apart. Turn key off and the light should be cleared. If not 2 other options, take to dealer and have him diagnose it. unhooking the battery will clear all faults but if the problem still existes it will come on again. hope this helps.