Fuel Tank Pressure Sensor

The PCM monitors the fuel tank pressure sensor to detect vacuum decay and excess vacuum during the EVAP system tests. The fuel tank pressure sensor measures the difference between the air pressure (or vacuum) in the tank and the outside air pressure. The PCM supplies a 5 volt reference and a ground for the fuel tank pressure sensor. The fuel tank pressure sensor provides a signal to the PCM that ranges between 0.1 and 4.9 volts.