When the headlight(light switch in the headlight or AUTO position) is on and all doors (and tailgate) are locked and closed, the headlight, position light and tail light will come on for 15 seconds if any of the below is performed.
At this time, if you press the door lock button (on the transmitter or smart key), the lights will turn off immediately.
Kia Cee'd JD Service Manual: Front Door Module Components and components location
Component Location
1. Front door module
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Kia Cee'd JD Service Manual: Blind Spot Detection Switch Repair procedures
Removal
1.
Disconnect the negative (-) battery terminal.
2.
Remove the crash pad lower panel.
(Refer to Body - "Crash Pad Lower Panel")
3.
Remove the lower crash pad switch assembly (A) ...