Tank ventilation

The tank vent valve controls the regeneration of the activated carbon canister by means of scavenging air. The scavenging air sucked in by the carbon canister accumulates hydrocarbons (HC) depending on the carbon filter load. 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.