Fuel Evaporation Valve

Fuel Evaporation Valve:

Check electrical function:

•D• 300 - The fuel evaporation valve is driven at intervals of one second. The actuation cycles can be felt with the hand.

Check for leaks:

Detach hoses from valve, switch on vacuum pump at service tester and connect to valve (8 mm connection) (note arrow indicating direction of flow). Set vacuum to 600 mbar and apply a voltage of 12 V to the valve.

Switch off vacuum pump, after 20 sec, the pressure drop must not exceed 50 bar.

When power is not applied, the valve is closed by a non-return valve to a vacuum of 20 mbar.

Check activation phases:

•D• 900 - The valve is activated at idle speed (display: ON or CLOSED) and is therefore closed. As soon as the emission control is active and the engine speed is increased, the valve can be seen to open step-by-step (display: OFF or OPEN). After switching off the engine, the valve is held closed for 3 to 5 sec.