Design

Evaporative emission (EVAP) system
The housing for the EVAP valve is plastic and contains a solenoid valve. The EVAP canister consists of a plastic holder with active carbon and a filter. Internally, the plastic holder is divided up into chambers depending on the market and the prevailing emissions requirements.

All the active carbon in the canisters is held by springs and pressure plates so that no air columns are created by vibration for example. This could lead to hydrocarbon leakage at the carbon beds. The connector pipe has a filter so that carbon dust cannot leak out and damage the leak diagnostic pump and the EVAP valve. The leak diagnostic pump consists of a plastic housing with an electric motor, pump, valves, leak calibration and a PTC heater element.