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.
Patent No.:
Date of Patent:
Sep. 24, 1996
Filed:
Apr. 28, 1995
Applicant:
Inventors:
Da Y Wang, Lexington, MA (US);
Larry M Oberdier, Royal Oak, MI (US);
Assignee:
General Motors Corporation, Detroit, MI (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G01N / ;
U.S. Cl.
CPC ...
204401 ; 204425 ; 204427 ; 204406 ; 123672 ; 123690 ; 205775 ;
Abstract
A diagnostic apparatus applied to internal combustion engine exhaust gas sensors employing electrochemical polarographic principles indicates sensor operation relative to a current limiting operating region in which a sensor output signal indicates oxygen concentration in the exhaust gas. A sensor drive signal is controllably perturbed and sensor sensitivity monitored by monitoring the sensor response to the perturbation. Current limiting operation may be diagnosed and indicated when the sensor response indicates an insensitivity to the perturbation.