Hyundai Sonata LF: Engine Control System / Injector Troubleshooting
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.

Other information:
Replacement
•
When prying with a flat-tip screwdriver or use a prying trim
tool, wrap it with protective tape, and apply protective tape around the
related parts, to prevent damage.
•
Use a plastic panel removal tool to remove interior trim pieces to protect from marring the surface...
Removal
•
In order to remove the panorama sunroof assembly, use the tools shown in the following figure:
[Tooling Diagram]
Square wire
Insert-type wire grip
[Tooling Assembly Diagram]
•
Insert and affix square wire into the insert hole of the wire grip ...