Fuel Evaporation Control Valve

Fuel Evaporation Control Valve:

Check electrical function:

•D• 3 - The fuel evaporation control 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 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 mbar.

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

Check activation phases:

•D• 2 - 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.