Tank ventilation valve
The fuel tank is ventilated via carbon canister to prevent fuel vapour from escaping into the atmosphere. The tank ventilation valve (TEV) clears fuel vapour from the carbon canister to prevent the carbon canister from becoming saturated. The fuel vapours are passed on to the intake manifold and combusted in the combustion chamber. The TEV is regulated by the pulse width modulation signal from the engine control unit.
The TEV switch is located on the belt disk side of the engine Motors.
If the TEV switch fails, the emission values can deteriorate. The driver might smell fuel, as the carbon canister is saturated. The MIL lights up.