Fuel Pressure Sensor: Description and Operation

Fuel Absolute Pressure Sensor
The fuel absolute pressure (FAP) sensor is integral to the compuvalve. It is a pressure transducer that converts pressure to voltage through a piezo-resistive element. This signal is monitored to make sure that the pressure regulator is functioning properly and is used to adjust the injector combination according to supply pressure. The FAP sensor allows the vehicle to start in ALT fuel mode at a minimum of 25 psia. It also controls when the vehicle will auto switch to gasoline (25 psia).