Fuel Tank Pressure Sensor

Fuel tank pressure sensor is installed on top of fuel tank. Fuel tank pressure sensor senses fuel vapor pressure in fuel tank and compares it with barometric pressure. PCM will convert pressure reading into a voltage signal. Fuel tank pressure sensor receives a 5-volt reference from PCM. As fuel tank pressure changes, resistance of sensor changes and sends a voltage signal back to PCM. PCM uses this signal to determine if a leak exists in EVAP system.