Title:
OXYGEN SENSOR DEVICE EQUIPPED WITH DYNAMIC HEATER ABNORMAL ACTION DETECTOR
Document Type and Number:
Japanese Patent JP3231517
Kind Code:
B2
Abstract:
PURPOSE: To provide a heated exhaust gas oxygen sensor assembly for an internal combustion engine, in which the state of a heater is changed in order to detect the abnormal action of the heater.
CONSTITUTION: An assembly includes an oxygen sensor 42, a heater 44, an impedance sensor, and a controller 38. The oxygen sensor 42 has a detecting element and a pair of output lead wires 54, 56, all of which are enclosed in a protective canister 58. The detecting element detects the relative oxygen concentration of exhaust gas and imparts oxygen level signals to the output lead wires 54, 56. The impedance sensor is connected to the output lead wires 54, 56 of the oxygen sensor 42 to measure the impedance between the wires 54, 56. The controller 38 first operates the heater 44 and then makes the heater non-operating. The controller 38 receives impedance signals indicating the impedance of the oxygen sensor 42 both when the heater 44 is switched on and when it is switched off. The controller 38 compares these two impedance levels, and if the difference (or ratio) between these two values does not meet a predetermined criterion, the controller 38 yields a heater abnormal action signal.
Inventors:
Ross Dee Persistent
Julie A. Conrad
Robert W. Ridgeway
Julie A. Conrad
Robert W. Ridgeway
Application Number:
JP26905693A
Publication Date:
November 26, 2001
Filing Date:
October 27, 1993
Export Citation:
Assignee:
FORD MOTOR COMPANY
International Classes:
G01N27/409; F02D41/14; (IPC1-7): G01N27/409
Attorney, Agent or Firm:
Akira Asamura (3 outside)