Leak Detection Solenoid: Description and Operation

The fuel tank pressure control solenoid valve is located in the evaporation line between the shutoff valve on fuel filler pipe and the fuel tank. It adjusts the fuel tank inside pressure under the control of the ECM.

When the tank inside pressure becomes higher than the atmospheric pressure, the valve is opened allowing fuel vapors to be introduced into the canister.

On the other hand, when the tank inside pressure becomes lower than the atmospheric pressure, external air is taken from the drain valve into the canister.

The pressure control solenoid valve can also be electrically closed for the system diagnosis purposes.