Diagnostic method for an exhaust gas probe and diagnostic device for an exhaust gas probe

US7499792B2 · kind B2 · utility

Assignee

• Siemens Aktiengesellschaft · DE

Inventors

• Gerd Rösel · Dresden, DE
• Norbert Sieber · Regensburg, DE

Key dates

• Filing date: Mar 30, 2007
• Grant date: Mar 3, 2009
• Expiry date: Aug 17, 2027

Classification

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

Abstract

An exhaust gas probe is disposed downstream of a catalytic converter in an exhaust gas tract of an internal combustion engine. A first quality value which is representative of a signal dynamic of the measured signal of the exhaust gas probe is determined as a function of the measured signal of the exhaust gas probe. If the first quality value represents at least one predefined signal dynamic, the exhaust gas probe is diagnosed as functioning correctly. If the first quality value does not represent at least the predefined signal dynamic, a catalytic converter diagnosis is performed comprising a loading with oxygen and/or an emptying of oxygen with at least two different air/fuel ratios. Dependent on the catalytic converter diagnosis, the exhaust gas probe is diagnosed as functioning either correctly or incorrectly.