If the high mounted stop lamp (LED) does not operate, we recommend that you checked an authorized Kia dealer.
Kia Niro (DE HEV) Owners Manual: To set vehicle to vehicle distance
This function allows you to program the vehicle to maintain relative distance
to the vehicle ahead without depressing the accelerator pedal or brake pedal.
The vehicle to vehicle distance will automatically activate when the smart cruise
control system is on.
Select the appropriate distance ...
Kia Niro (DE HEV) Owners Manual: To decrease the crusie control set speed
Follow either of these procedures:
Move the lever down (to SET-), and hold it. Your vehicle set speed will
decrease by 10 km/h (5 mph). Release the lever at the speed you want.
Move the lever down (to SET-), and release it immediately. The cruising
speed will decrease by 1.0 km/h (1.0 ...