METHOD OF TESTING FOR LEAKAGE OF VEHICLE FUEL SYSTEM (VERSIONS) AND METHOD FOR HYBRID VEHICLE Russian patent published in 2018 - IPC B60W20/50 F02D41/00 F02D41/32 F02M25/08 

FIELD: internal combustion engines.

SUBSTANCE: invention relates to vehicle fuel systems. Method of testing a vehicle fuel system for leakage comprises, in the first state, receiving an indication of a first engine-off event and an indication that heat preservation during the first engine-off event should increase the likelihood of a successful natural vacuum test when the engine is off. After the first engine-off event, the tank vent valve is closed based on the indication of heat preservation without initiating a natural vacuum test with the engine off. Further, an indication of an engine on event is received and the tank vent valve is opened after engine on event. In a second state, following the first state, an indication of an engine off event is received, which is a second engine off event. After the engine off event, the tank vent valve is closed based on the vehicle off event and a natural vacuum test is initiated with the engine off.

EFFECT: improved leakage inspection.

17 cl, 7 dwg