When the headlight (light switch in the headlight or AUTO position) is on and all doors (and tailgate) are locked and closed, the position light and headlight will come on for 15 seconds if any of the below is performed.
At this time, if you press the door lock or unlock button, the position light and headlight will turn off immediately.
Kia Niro 2017 (DE HEV) Service Manual: Rear Seat Belt Buckle Repair procedures
Replacement
When installing the belt, be careful not to damage the retractor.
1.
Remove the rear seat cushion assembly.
(Refer to Rear Seat - "Rear Seat Assembly")
...
Kia Niro (DE HEV) Owners Manual: Owner maintenance precautions
Improper or incomplete service may result in problems. This section gives instructions
only for the maintenance items that are easy to perform.
✽ NOTICE
Improper owner maintenance during the warranty period may affect warranty
coverage. For details, read the separate Warranty & Maintenan ...