Abstract: Methods and systems for improving vacuum generation for an engine that may be operated at higher altitudes are presented. In one non-limiting example, a transmission that is mechanically coupled to the engine may be shifted from a gear to neutral in response to an actual total number of times a vehicle brake pedal is applied and partially released while the vehicle is stopped and the brake pedal is applied.

Abstract: Methods and systems for improving vacuum generation for an engine that may be operated at higher altitudes are presented. In one non-limiting example, a transmission that is mechanically coupled to the engine may be shifted from a gear to neutral in response to an actual total number of times a vehicle brake pedal is applied and partially released while the vehicle is stopped and the brake pedal is applied.

Abstract: Methods and systems for improving vacuum generation for an engine that may be operated at higher altitudes are presented. In one non-limiting example, a transmission that is mechanically coupled to the engine may be shifted from a gear to neutral in response to an actual total number of times a vehicle brake pedal is applied and partially released while the vehicle is stopped and the brake pedal is applied.

Abstract: Methods and systems for improving vacuum generation for an engine that may be operated at higher altitudes are presented. In one non-limiting example, a transmission that is mechanically coupled to the engine may be shifted from a gear to neutral in response to an actual total number of times a vehicle brake pedal is applied and partially released while the vehicle is stopped and the brake pedal is applied.

Abstract: Methods and systems are provided for reducing the generation and transmission of objectionable noise from an aspirator to a vehicle cabin during vacuum production. During selected conditions, motive flow through an intake aspirator may cause a hissing noise to be produced at the aspirator, and transmitted through an open check valve in a bypass path between the aspirator and a vacuum reservoir, into a vehicle cabin. During these conditions, an aspirator shut-off valve is closed to reduce motive flow through the aspirator, thereby reducing the hissing noise.

Abstract: A system and method for conserving vacuum within a vehicle is described. In one example, a vacuum level in a working chamber of a vacuum operated brake booster is controlled so as to limit vacuum consumption.

Abstract: An electric vacuum pump backup control system includes a brake on/off switch, a primary electric vacuum pump control interfacing with the brake on/off switch, a secondary electric vacuum pump control interfacing with the brake on/off switch and the primary electric vacuum pump control and an electric vacuum pump interfacing with the primary electric vacuum pump control.

Abstract: Methods and systems are provided for reducing the generation and transmission of objectionable noise from an aspirator to a vehicle cabin during vacuum production. During selected conditions, motive flow through an intake aspirator may cause a hissing noise to be produced at the aspirator, and transmitted through an open check valve in a bypass path between the aspirator and a vacuum reservoir, into a vehicle cabin. During these conditions, an aspirator shut-off valve is closed to reduce motive flow through the aspirator, thereby reducing the hissing noise.

Abstract: A system and method for conserving vacuum within a vehicle is described. In one example, a vacuum level in a working chamber of a vacuum operated brake booster is controlled so as to limit vacuum consumption.

Abstract: An electric vacuum pump backup control system includes a brake on/off switch, a primary electric vacuum pump control interfacing with the brake on/off switch, a secondary electric vacuum pump control interfacing with the brake on/off switch and the primary electric vacuum pump control and an electric vacuum pump interfacing with the primary electric vacuum pump control.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.