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. 21, 1993
Filed:
Oct. 28, 1992
Ross D Pursifull, Dearborn, MI (US);
Julie A Konrad, Dearborn, MI (US);
Robert W Ridgway, Royal Oak, MI (US);
Ford Motor Company, Dearborn, MI (US);
Abstract
A heated exhaust gas oxygen sensor assembly for an internal combustion engine that changes the heater status in order to detect a malfunction of the heater. The assembly includes an oxygen sensor, heater, impedance sensor, and controller. The oxygen sensor has a sensing element and a pair of output leads. The sensing element detects the relative oxygen concentration in the exhaust gas and responsively provides an oxygen level signal on the output leads. The heater physically warms the oxygen sensor. The impedance sensor is interconnected to the output leads of the oxygen sensor and measures the impedance between them. The controller first activates and then deactivates the heater. The controller also receives the impedance signals representing the impedance of the oxygen sensor when the heater is both on and off. The controller compares these two impedance levels and, if the difference between (or ratio of) these two values fails to meet a predetermined standard, the controller issues a heater malfunction signal. The malfunction signal may then alert the driver or mechanic that a heater malfunction has been detected.