Fuel Tank Pressure Sensor: Description and Operation

Fuel Tank Pressure Sensor:

The fuel tank pressure sensor is installed on top of the fuel tank. The fuel tank pressure sensor senses the fuel vapor pressure in the fuel tank and compares it with the barometric pressure. The PCM will then convert the pressure reading into a voltage signal. The PCM uses this signal as one of the inputs to detect an EVAP control system malfunctions.

The fuel tank pressure sensor is similar to the Manifold Absolute Pressure (MAP) Sensor. The fuel tank pressure sensor measures the difference between the air pressure (or vacuum) in the fuel tank and the atmospheric pressure. The PCM supplies a 5 volt reference and a ground to the sensor. The sensor sends a voltage signal between 0.1 and 4.9 volts back to the PCM. When the fuel cap is removed, the air pressure in the fuel tank is equal to the atmospheric pressure and the output voltage of the sensor will range from 2.0 to 2.5 volts.