When your brake pads are worn and new pads are required, you will hear a high-pitched warning sound from your front brakes or rear brakes (if equipped). You may hear this sound come and go or it may occur whenever you depress the brake pedal.
Please remember that some driving conditions or climates may cause a brake squeal when you first apply (or lightly apply) the brakes. This is normal and does not indicate a problem with your brakes.
CAUTION
WARNING - Brake wear
This brake wear warning sound means your vehicle needs service. If you ignore this audible warning, you will eventually lose braking performance, which could lead to a serious accident.
Kia Niro 2017 (DE HEV) Service Manual: Battery Sensor Repair procedures
Removal
1.
Open the trunk.
2.
Remove the luggage side trim [RH].
(Refer to Body - "Luggage Side Trim")
3.
Turn ignition switch OFF and disconnect the battery negative (-) terminal
(A).
...
Kia Niro 2017 (DE HEV) Service Manual: Rear Wheel Speed Sensor Repair procedures
Removal
1.
Remove the tire.
2.
Disconnect the wheel speed sensor connector (A).
3.
Loosen the bearing bolts (A) and then remove the hub bearing assembly.
Tightening torque:
88.2 - 10 ...