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:
Removal and Installation
1.
Remove the cooling fan.
(Refer to Cooling System - "Cooling Fan")
2.
Loosen the drain plug, and drain the coolant.
3.
Remove the radiator cap to speed draining.
4.
Remove the radiator upper hose (A) and lowr hose (B)...
Components and Components Location
Component Location
1. DDM (Driver Door Module)2. ADM (Assist Door Module)3. SJB (Smart Junction Block)4. Door lock knob5. Trunk lid actuator6. Door latch module7. Door lock/unlock switch8. RLDM (Rear Left Door Module)9...