| Signal Waveform |
The three waveforms below are taken from the #1 and #4 injectors. The top waveform is from the high side (feed side) of the #1 and #4 injectors, while the middle waveform is from the low side (ground side) of the #1 injector and the bottom waveform is from the low side of the #4 injector.
The middle waveform is the same as the top waveform because there is no ground for the circuit. With no current flowing in the circuit, the #1 injector is not energized and fuel does not flow.
The bottom waveform shows that ground is supplied and there is a voltage drop across the #4 injector. With current flowing in the circuit, the #4 injector is energized and fuel flows.

Injector Repair procedures
Purge Control Solenoid Valve (PCSV) SpecificationsKia Niro 2017 (DE HEV) Service Manual: Injector Specifications
Specification
Item
Specification
Coil Resistance (Ω)
1.425 - 1.575 [20°C(68°F)]
...
Kia Niro 2017 (DE HEV) Service Manual: Description and operation
Description
If the Gasoline Engine Control system components (sensors, ECM, injector, etc.)
fail, interruption to the fuel supply or failure to supply the proper amount of
fuel for various engine operating conditions will result. The following situations
may be encountered.
...