The purpose of the air bag warning light in your instrument panel is to alert you of a potential problem with your air bag - Supplemental Restraint System (SRS).
When the ignition switch is turned ON, the warning light should illuminate for approximately 6 seconds, then go off.
Have the system checked if:
Kia Niro 2017 (DE HEV) Service Manual: Components and components location
Components
1. Front oil seal
2. Timing chain cover
3. Variable force solenoid (VFS) valve
4. O-ring
5. Timing chain tensioner
6. Timing chain tensioner arm
7. Timing chain guide
8. Timing chain
9. Timing chain cam guide
...
Kia Niro (DE HEV) Owners Manual: Use high quality ethylene glycol coolant
Your vehicle is delivered with high quality ethylene glycol coolant in the cooling
system. It is the only type of coolant that should be used because it helps prevent
corrosion in the cooling system, lubricates the water pump and prevents freezing.
Be sure to replace or replenish your coolant ...