This warning light illuminates:
CAUTION - Malfunction Indicator Lamp (MIL)
Driving with the Malfunction Indicator Lamp (MIL) on may cause damage to the emission control systems which could affect drivability and/or fuel economy.
CAUTION - Gasoline Engine
If the Malfunction Indicator Lamp (MIL) illuminates, potential catalytic converter damage is possible which could result in loss of engine power. In this case, we recommend that you have the vehicle inspected by an authorized Kia dealer as soon as possible.
Kia Niro 2017 (DE HEV) Service Manual: Fuel Tank Repair procedures
Removal
1.
Switch "OFF" the ignition and disconnect the negative (-) battery terminal.
2.
Remove the rear seat cushion.
(Refer to Body - "Rear Seat Assembly")
3.
Fuel pump service cover (A).
...
Kia Niro 2017 (DE HEV) Service Manual: Special service tools
Special Service Tools
Tool Name / Number
Illustration
Description
Insulated Tool Set
0K375-4U000
Used for measuring or working on high voltage parts-22 components (Including
case)
-22EA compon ...