Fuel Pressure Sensor: Description and Operation

Fuel Rail Pressure (FRP) Sensor:

The [1][2]fuel pressure sensor senses the pressure difference between the fuel injection supply manifold and the intake manifold, and provides the powertrain control module with the current fuel injection supply manifold pressure. The return fuel line to the fuel tank has been deleted in this type of fuel system.

The powertrain control module uses this information to vary the duty cycle output to the Fuel Pump Driver Module (FPDM) which controls the speed of the fuel pump. The speed of the fuel pump sustains fuel injection supply manifold pressure which preserves fuel in its liquid state.

The dynamic range of the fuel injectors increase is due to the higher pressure, which allows the injector pulse width to decrease.







The [1][2]fuel pressure sensor:
^ is located on the RH side of the fuel injection supply manifold downstream of the fuel injectors.
^ maintains fuel pressure to the fuel injectors based on intake manifold vacuum.