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:
Aug. 05, 2003
Filed:
Mar. 19, 2001
Martin Leven, West Bloomfield, MI (US);
William J. Morgan, Dewitt, MI (US);
General Motors Corporation, Detroit, MI (US);
Abstract
An improved assembly method and a corresponding diagnostic method carried out by an electronic engine control module in a factory test setting reliably and inexpensively verifies correct matching of a vehicle engine and an exhaust gas oxygen sensor installed on an exhaust pipe thereof. Heating elements within the oxygen sensors are manufactured so as to exhibit an electrical resistance that is different for each type of sensor. Due to normal part-to-part tolerance variation, the heater resistance of one type of oxygen sensor falls into a first range, and the heater resistance of the other type of oxygen sensor falls into a second range. The electronic control module for each engine is calibrated as part of its overall fuel control calibration, to recognize an oxygen sensor current requirement range corresponding to the respective fuel control (i.e., leaded or unleaded). The electronic control module operates during an initial period of engine operation during factory testing prior to convergence of the first and second resistance ranges to measure the average current supplied to the installed oxygen sensor, and to compare the measured current with the calibrated current requirement range. The comparison is used to set a diagnostic indicator, which is checked to determine if the engine should be directed to the next assembly area or returned to a repair area so that the correct sensor may be installed.