Evaporative emission control components (Emission control - V8)

The fuel evaporation leak detection is part of the On-Board Diagnostics (OBD) strategy and it is able to determine vapour leaks from holes or breaks down to 0.5 mm (0.02 in.) diameter. Any fuel evaporation leaks which occur between the output of the purge valve and the connection to the inlet manifold cannot be determined using this test, but these will be detected through the fuelling adaption diagnostics.

Evaporative emission control components

The evaporative emission control components and the fuel evaporation leak detection test components (NAS only) are described below:

Fuel vapour separator (NAS version illustrated)

1 Filler neck 2 Filler cap 3 Liquid vapour separator (LVS) 4 To fuel tank 5 Vapour from fuel tank to liquid vapour separator (LVS) 6 Rubber hose

7 Pipe connection to OBD sensor in fuel pump (NAS vehicles with vacuum type leak detection system only) 8 Vent pipe to EVAP canister 9 Anti-trickle valve (NAS only)

The fuel vapour separator is located under the rear wheel arch next to the filler neck and protected by the wheel arch lining. The connections to the separator unit are quick release devices at the end of the flexible hoses which connect the fuel tank to the inlet side of the separator and the outlet of the separator to the evaporation vent line.

The fuel separator construction is different between NAS and ROW vehicles; the LVS on NAS vehicles is an L-shaped metal tube and for all other markets is an integral part of the moulded plastic filler neck.