Fuel Tank Pressure Sensor: Description and Operation

Pressure Sensor, EVAP (585)

A differential pressure sensor is mounted on the tank. It compares the pressure in the tank with barometric pressure.

The pressure sensor is powered with 5V from the electronic control module.

Depending on the pressure difference between the tank and atmosphere, a proportional voltage is sent from the pressure sensor to the control module.

When there is no pressure difference, the voltage from the pressure sensor is approx. 2.5 V.

The pressure sensor is used for OBD II diagnosis on cars with full ORVR. ORVR (Onboard Refuelling Vapour Recovery) without tank integrity diagnosis does not have a tank pressure sensor.