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:
Apr. 09, 1996
Filed:
Mar. 10, 1995
Satyadeo N Sinha, Canton, MI (US);
Raymond H Berger, Dearborn, MI (US);
Ford Motor Company, Dearborn, MI (US);
Abstract
A method and system for reducing emissions from an engine during periods of partial or total heated exhaust gas oxygen (HEGO) sensor failure. A switch point is stored in an electronic engine control for use in controlling the fuel delivered to the engine based on the value of the signal generated by the oxygen sensor relative to the switch point. The method includes the step of sensing the current of the heater element of the HEGO sensor. The sensed current is compared to a first predetermined current threshold which indicates a degradation of the HEGO sensor. A degradation of the HEGO sensor introduces a bias signal to the electronic engine control. If the current of the heater element is below the first predetermined current threshold but not below a second predetermined current threshold, the switch point is changed so as to compensate for degradation of the oxygen sensor. The electronic engine control then controls the delivery of fuel to the engine based on the value of the signal generated by the oxygen sensor relative to the changed switch point until the HEGO sensor is replaced.