Tank ventilation

The tank vent valve controls the regeneration of the activated carbon canister by means of scavenging air. Scavenging air drawn through the activated carbon canister 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 creation of hydrocarbons in the fuel tank depends on:

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

The tank vent valve is closed when in a de-energized state. This prevents the ingress of fuel vapor from the activated carbon canister into the intake pipe when the engine is at a standstill.