METHOD AND SYSTEM FOR VACUUM GENERATION

摘要

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.

主权项

1. A method for an engine, comprising:
closing a first valve coupled between a vacuum reservoir and an intake manifold, upstream of an aspirator, responsive to opening of a second valve coupled between the vacuum reservoir and the intake manifold, downstream of the aspirator.