초록 ▼

A method and system for fuel vapor control in a hybrid vehicle (HEV). The HEV fuel vapor recovery system includes a fuel tank isolation valve, which is normally closed to isolate storage of refueling from storage of diurnal vapors. The method for fuel vapor control includes selectively actuating the

A method and system for fuel vapor control in a hybrid vehicle (HEV). The HEV fuel vapor recovery system includes a fuel tank isolation valve, which is normally closed to isolate storage of refueling from storage of diurnal vapors. The method for fuel vapor control includes selectively actuating the fuel tank isolation valve during interrelated routines for refueling, fuel vapor purging, and emission system leak detection diagnostics to improve regulation of pressure and vacuum the HEV fuel vapor recovery system.

대표청구항 ▼

The invention claimed is: 1. A vehicle system, comprising,a battery;an engine including an engine intake, the engine selectively started in response to a battery state of charge falling below a threshold;a fuel tank coupled to a canister through a fuel tank isolation valve;a canister, configured to

The invention claimed is: 1. A vehicle system, comprising,a battery;an engine including an engine intake, the engine selectively started in response to a battery state of charge falling below a threshold;a fuel tank coupled to a canister through a fuel tank isolation valve;a canister, configured to store fuel vapors, coupled to an engine intake through a canister purge valve, the canister further coupled to a vacuum accumulator through a vacuum accumulator valve;a first pressure sensor coupled to the fuel tank to estimate a fuel tank pressure;a second pressure sensor coupled to the canister to estimate a canister pressure; anda control system with computer readable instructions for,during an engine-off mode of operation, with the fuel tank isolation valve opened and the canister purge valve closed,applying a pressure on the fuel tank first and then the canister, when an absolute value of the fuel tank pressure is above a threshold;applying a pressure on the canister first and then the fuel tank, when the absolute value of the fuel tank pressure is below a threshold;indicating fuel tank isolation valve and/or canister purge valve degradation based on a change in the fuel tank pressure and the canister pressure following pressure application.