Method and device for monitoring a secondary-air system of a motor vehicle

US5542292A · kind A · utility

Assignee

• Robert Bosch GmbH · DE

Inventors

• Erich Schneider · Tauberbischofsheim, DE
• Rainer Bone · Leinfelden, DE
• Martin Klenk · Munich, DE
• Jorg Lange · Eberdingen, DE
• Dieter-Andreas Dambach · Ditzingen, DE

Key dates

• Filing date: Dec 14, 1994
• Grant date: Aug 6, 1996
• Expiry date: Dec 14, 2014

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y02T10/40
• WIPO field: Engines, pumps, turbines
• WIPO sector: Mechanical engineering

Abstract

In a method and device for monitoring a secondary-air system, a first value is determined which characterizes the secondary air stream blown by the secondary-air system into the exhaust-gas channel of an internal combustion engine. On the basis of this first value, the functioning of the secondary-air system is judged. If the first value lies within a predeterminable interval, it is concluded that the secondary-air system is operating properly. If the first value, on the other hand, lies outside of this predeterminable interval, it is concluded that a malfunction is present. The first value is determined from a second value which characterizes the stream of air fed to the internal combustion engine, from the air/fuel ratio of the mixture drawn in by the internal combustion engine, and from the air/fuel ratio prevailing in the exhaust-gas channel downstream of the place of introduction of the secondary-air line.