Tank ventilation

The fuel evaporation control valve controls the regeneration of the activated carbon filter with scavenging air.

Scavenging air drawn through the activated carbon filter is enriched with hydrocarbons (HC) depending on the loading of the activated carbon. The scavenging air is subsequently fed to the engine for combustion.

The formation of hydrocarbons in the fuel tank is dependent on:

• Fuel temperature and ambient temperature
• Air pressure
• Fill level in the fuel tank

In a current-free state, the fuel evaporation control valve is closed. This prevents the ingress of fuel vapor from the activated carbon filter into the inlet pipe when the engine is switched off.