Hyundai Sonata LF: Fuel Delivery System / Fuel Pressure Sensor (FPS) Description and Operation
The fuel pressure sensor (FPS) is installed on the top of the
low pressure fuel pump and measures the pressure in the low pressure
fuel line.
Based on the fuel pressure measured by the FPS and the amount
of fuel consumed, the fuel pump control module (FPCM) determines
whether to activate the low pressure fuel pump.
After activating the low pressure fuel pump, the FPS
continues to provide the fuel pressure information to the FPCM and the
FPCM keeps controlling the fuel flow rate using the feedback information
from the FPS.

Removal
1.
Turn the ignition switch OFF and disconnect the battery negative (-) cable.
2.
emove the rear seat cushion.
( Refer to Body - "Rear Seat Assembly")
3...
Other information:
C..
Removal
1.
Disconnect the negative (-) battery terminal.
2.
Loose the nuts (4EA) holding the rear combination lamp then
disconnect the connector (A) then remove the outside rear combination
lamp assembly.
3.
Remove the bulb (A) after turnicng in the counter clock-wise direction...