Fuel Tank Pressure Sensor: Description and Operation

The fuel tank pressure (FTP) sensor measures the difference between the pressure or vacuum in the fuel tank and the outside air pressure. The FTP sensor mounts in the top of the fuel tank-sending unit. The PCM provides a 5-volt reference and a ground to the FTP sensor. The FTP sensor provides a signal voltage back to the PCM that can vary between 0.1 and 4.9 volts. As fuel tank pressure increases, FTP sensor voltage decreases. As fuel tank pressure decreases, FTP voltage increases .