Fuel Tank Pressure Sensor
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The Fuel Tank Pressure (FTP) sensor is located on top of the fuel sender assembly. See Figure. FTP sensor measures the difference between the pressure or vacuum in the fuel tank and outside air pressure. The Powertrain Control Module (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 0.1-4.9 volts. As FTP increases, FTP sensor voltage decreases, high pressure = low voltage. As FTP decreases, FTP voltage increases, low pressure or vacuum = high voltage.