Sensor-Fuel Pressure: Description
WARNING: This page is about a different car, the 2006 Dodge Magnum, 2006 Dodge Charger, and 2006 Chrysler 300. However, it is still accessible from the selected car via links, so may be relevant.
The fuel rail pressure sensor monitors and passes on the current fuel rail pressure to the ECM. The non-constant system pressure influences the position of the sensor diaphragm which alters the sensors electrical resistance.