Non-intrusive diagnostic tool for sensing oxygen sensor operation

• US 20050096806A1
• Filed: 11/03/2003
• Published: 05/05/2005
• Est. Priority Date: 11/03/2003
• Status: Active Grant

• Current Assignee: Delphi Technologies Ip Limited (BorgWarner Incorporated)
• Original Assignee: Delphi Technologies, Inc. (BorgWarner Incorporated)
• Inventors: Diem, Earl D.
• Granted Patent: US 6,947,817 B2
• Time in Patent Office: Days
• US Class Current: 701/29
• CPC Class Codes: F01N 11/00 Monitoring or diagnostic devices for exhaust-gas treatment apparatus , e.g. for catalytic activity safety, indicating or supervising devices for internal combustion engines F02B77/08; testing of machines G01M13/00
• CPC Class Codes: G01N 27/4175 Calibrating or checking the analyser

Abstract

A diagnostic testing system for a vehicle includes an oxygen sensor, an analyzer having a user interface, and a communications link between the analyzer and the vehicle to obtain data from the oxygen sensor. A diagnostic heuristic is used to analyze the data and confirm proper operation of the sensor; and an output is generated by said diagnostic heuristic to the user interface. This abstract is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims.

Claims

1. A diagnostic testing system for a vehicle comprising comprising:

an analyzer having a user interface;

a communications link between said analyzer and said vehicle to obtain data from said oxygen sensor and engine throttle position obtained generally concurrently with said data from said oxygen sensor, said data from said oxygen sensor includes a voltage between an upper voltage and a lower voltage in a generally sinusoidal manner over time;

a diagnostic heuristic to analyze said data and confirm proper operation of said sensor, said diagnostic heuristic comprising correlating engine throttle position with said data from said oxygen sensor over said time period and measuring a time period between said upper voltage and said lower voltage; and

an output generated by said diagnostic heuristic to said user interface including the results generated by said diagnostic heuristic.

6. A diagnostic testing system as in claim 1, wherein a cross-count voltage is established between said upper voltage and said lower voltage, and wherein a time period is set and the number of counts measured where said voltage matches said cross-count voltage within said time period.

7. A diagnostic testing system as in claim 6, wherein said data includes engine RPM obtained generally concurrently with said data from said oxygen sensor such that said engine RPM can be correlated with said data from said oxygen sensor over said time period.

8. A diagnostic testing system as in claim 1, wherein said data is collected over a predetermined time for use by said diagnostic heuristic.

9. A diagnostic testing system as in claim 1, wherein said diagnostic heuristic includes a set of instructions presented through said user interface.

10. A diagnostic testing system as in claim 9, wherein a said set of instructions includes pre-validation system check.

2-5. -5. (canceled)

11. A diagnostic testing system for a running vehicle having an internal combustion engine and an oxygen sensor received within to an exhaust stream of said internal combustion engine, comprising:

an analyzer having a user interface;

a communications link between said analyzer and said vehicle to obtain data from said oxygen sensor, and wherein said data from said oxygen sensor includes a voltage, said voltage ranging between an upper voltage and a lower voltage in a generally sinusoidal;

a diagnostic heuristic to analyze said data and confirm proper operation of said sensor, said diagnostic heuristic comprising a first test to measure a first time period between said upper voltage and said lower voltage and to determine whether said first time period is within a pre-set threshold and, if said first time period is within said pre-set threshold, a second test to establish a cross-count voltage between said upper voltage and said lower voltage and to determine a number of counts where said voltage matches said cross-count voltage within a second time period such that said sensor passes a second test if said number of counts is within a pre-set threshold; and

an output generated by said diagnostic heuristic to said user interface.

14. A diagnostic testing system as in claim 11, wherein prior to said first test, said system includes pre-test validation, said pre-test validation including confirming sensor communication;

module indicator light and diagnostic trouble code analysis;

engine RPM; and

sensor temperature.

15. A diagnostic testing system as in claim 14, wherein said sensor temperature is determined as a function of coolant temperature.

12-13. -13. (canceled)

16. A method for diagnostic testing of an oxygen sensor within a vehicle, the method comprising:

configuring a user interface in communication with a software system;

configuring a communications link in communication with said software system;

said software system communicating with an oxygen sensor;

conducting a pre-validation test using said software system; and

conducting a diagnostic test of said oxygen sensor using said software system, said diagnostic test comprising correlating engine throttle position with said data from said oxygen sensor and measuring a first time period between an upper voltage and a lower voltage, and wherein said diagnostic test further includes the steps of;

setting a cross-count voltage;

determining a cross count value for said oxygen sensor based upon the number of times said voltage crosses said cross-count voltage over said time period; and

comparing said cross count value to a pre-set threshold to confirm operation of said sensor.

17. The method of claim 16, wherein said pre-validation test further includes configuring an interface between said software system and an on-board vehicle computer system and testing for stored trouble codes in said on-board vehicle computer system.

18. The method of claim 16, wherein said pre-validation test further includes configuring an interface between said software system and an on-board vehicle computer system and testing for sensor temperature.

19. The method of claim 16, wherein said pre-evaluation test includes determining sensor temperature uses using engine coolant temperature.

20. The method of claim 16, wherein said diagnostic testing of said oxygen sensor further includes collecting a plurality of voltage readings of said oxygen sensor over a set time period.

22. A method of claim 20, wherein said diagnostic testing of said oxygen sensor further includes the steps of:

establishing an upper voltage and a lower voltage;

measuring the time for said voltage to move between one of said upper voltage and said lower voltage or said lower voltage and said upper voltage; and

comparing the time to a pre-set threshold to confirm operation of said sensor.

21. (canceled)