Detailed technical information
The evaporative emission control system filters steam from the fuel tank via a coal container. The solenoid valve, which is usually open, allows this filtered air to escape the system.
According to OBD II, the vehicle must carry out a self-test and ensure that no emission leaks are present in the evaporative emission control system. To carry out this test, the solenoid valve is energised so that the valve closes and the system is sealed.