The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.

The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.

Date of Patent:
Sep. 28, 1999

Filed:

Mar. 12, 1997
Applicant:
Inventors:

Claudio Carnevale, Nole Canavese, IT;

Paola Bianconi, Turin, IT;

Stefano Sgatti, Imola, IT;

Assignee:
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
F01N / ;
U.S. Cl.
CPC ...
60274 ; 60276 ; 60285 ; 123688 ;
Abstract

The method of diagnosis determines the state of deterioration of an exhaust gas stoichiometric composition sensor placed downstream of a catalytic converter. The catalytic converter is mounted on an exhaust manifold of an internal combustion engine supplied with an air/fuel mixture, while the sensor generates an output signal correlated with the stoichiometric composition of the mixture. The method comprises the phases of registering a temperature signal correlated with the temperature of the engine; determining the operating range of the engine; determining the stoichiometric composition of the air/fuel mixture; and effecting a hot diagnosis should the temperature signal be greater than a preset reference value, the engine be in the idle operating range and the sensor register a weak stoichiometric composition of the mixture. The hot diagnosis comprises the phases of generating control signals for the engine and of gauging the output signal from the sensor.


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