Description & Operation
Vehicle is equipped with an On-Board Diagnostic Stage II (OBD-II) system to meet enhanced emission control requirements. Within this OBD-II system, an On-Board Refueling Vapor Recovery (ORVR) system has been developed and equipped to meet enhanced evaporative emission control requirements during vehicle moving, parking, and refueling at gas stations.
ORVR system adopts one canister to collect both evaporative vapors during moving and parking as well as refueling vapor. Collected vapor is consumed by engine through intake manifold during vehicle operation. ORVR system creates suction inside filler neck by aid of fuel flow through a reduced diameter section in filler pipe.
ORVR system adopts so called "Liquid Trap" or "Liquid Seal" system that assures long term durability. System provides nozzle compatibility with conventional and stage 11 vapor recovery nozzle. System has been designed to have following functional features.
- To collect refueling vapors and to route to canister.
- To provide nozzle compatibility with conventional and stage 11 vapor recovery nozzles.
- To provide fill-shut off signal.
- To prevent canister from liquid fuel during normal driving and vehicle rollover.
- To provide fuel tank venting to canister during vehicle operation.
- To protect fuel tank from over-pressure.
- To protect fuel vapor dome from overfill.