Vehicle diagnostic tool—utilizing fuel trim data

• US 8,135,509 B1
• Filed: 11/23/2009
• Issued: 03/13/2012
• Est. Priority Date: 06/08/2006
• Status: Active Grant

• Current Assignee: Bernie C. Thompson, Neal R. Pederson
• Original Assignee: Bernie C. Thompson, Neal R. Pederson
• Inventors: Thompson, Bernie C., Pederson, Neal R.
• Primary Examiner(s): Black, Thomas
• Assistant Examiner(s): Olsen, Lin B
• Application Number:
  US12/624,085
• Time in Patent Office: 841 Days
• Field of Search: 701/35
• US Class Current: 701/29
• CPC Class Codes: G01M 15/04 Testing internal-combustion engines
• CPC Class Codes: G01M 15/05 by combined monitoring of two or more different engine parameters
• CPC Class Codes: G07C 5/0808 Diagnosing performance data testing of vehicles G01M17/00; testing of electrical installation on vehicles G01R31/005

Abstract

An analysis tool which extracts all the available parameter identifications (i.e. PIDS) from a vehicle'"'"'s power train control module for diagnostic decisions. This is done by checking these PIDS and other information (e.g., calculated PIDS, Break Points, charts and algorithms) in three states; key on engine off, key on engine cranking, key on engine running. In all three modes the tool is comparing the live data from PIDS and voltage to the other information (e.g, Break Points). If any of this data are outside the programmed values a flag is assigned to the failure or control problem. The relationship between a particular PID and its associated preprogrammed value(s) may be indicated by a light. The depth of the problem (if any) is conveyed by the color of the light. Also included are tests/charts for fuel trim, engine volumetric efficiency, simulated injector, power, catalyst efficiency, and engine coolant range.

Claims

1. A method of providing information on the operating condition of a Power Plant utilizing fuel trim data;

the Power Plant including an engine and a powertrain control module;

the method utilizing instrumentation including a microprocessor, and a chart of load on the engine (hereinafter “

engine load(s)”

) vs. the speed of the engine (hereinafter “

engine speed(s)”

);

the chart being divided into a number of cells, each cell representing a range of engine loads vs. engine speeds wherein no two cells have both the same range of engine loads and the same range of engine speeds;

the microprocessor being programmed to extract parameter identification data (hereinafter “

PID data”

) from the powertrain control module;

the microprocessor being further programmed to determine engine speed;

the method including the steps of;

a. acquiring PID data with the instrumentation, including PID data that provides information on the engine load (hereinafter “

engine load PID data”

) and fuel trim PID data, from the powertrain control module;

b. changing both the engine speed and the engine load;

c. determining, with the microprocessor, engine speed as the engine speed is changing; and

d. assigning fuel trim PID data as such data is acquired to different ones of the cells as both the engine speed and engine load change.

2. The method as set forth in claim 1, wherein the steps of acquiring PID data and assigning PID data includes the steps of acquiring and assigning fuel trim PID data from at least one of the group including LTFTB1 (Long Term Fuel Trim Bank 1) PID data STFTB1 (Short Term fuel Trim Bank 1) PID data, LTFTB2 (Long Term Fuel Trim Bank 2) PID data (if available), and STFTB2 (Short Term Fuel Trim Bank 2) PID data (if available).

3. The method as set forth in claim 2, wherein the microprocessor is programmed with one or more algorithms for processing acquired fuel trim PID data to create one or more calculated total fuel trim PIDs (hereinafter “

Total Trim”

), and wherein the step of assigning PID data also includes the step assigning Total Trim data to different ones of the cells as both the engine speed and load change.

4. The method as set forth in claim 1, wherein the steps of acquiring engine load PID data is the step of acquiring absolute throttle position thereinafter “

ATP”

) PID data.

5. The method as set forth in claim 1, wherein the step of acquiring engine load PID data includes the step of selecting from the group including ATP PID data, mass air flow (hereinafter “

MAF”

) PID data, manifold pressure (hereinafter “

MAP”

) PID data, and CALCULATED LOAD PID data.

6. The method as set forth in claim 1, further including the steps of dividing possible fuel trim values into a series of ranges and assigning to each range of fuel trim values a distinct code.

7. The method as set forth in claim 6, further including the step of providing a first code for fuel trim values between −

A and +A.

8. The method as set forth in claim 7, further including the step of providing a second code for fuel trim values between −

A and −

B and between +A and +B, wherein the absolute value of B is greater than the absolute value of A.

9. The method as set forth in claim 8, further including the step of providing a third code for fuel trim values between −

B and −

C and between +B and +C, wherein the absolute value of C is greater than the absolute value of B.

10. The method as set forth in claim 9, further including the step of providing a fourth code for fuel trim values greater than +C and less than −

C.

11. The method as set forth in claim 10, wherein the instrumentation also includes a display screen, and further including the steps of displaying the fuel trim PID data assigned to different cells on the display screen, and assigning a different color for each different code.

12. The method as set forth in claim 11, wherein the step of assigning different colors to different codes includes the steps of assigning green to the range −

A to +A, red to fuel trim values greater than +/−

C, one of yellow and orange to the range of −

A to −

B and +A to +B, and the other of yellow and orange to the range of −

B to −

C and +b to +C.

13. The method as set forth in claim 12, further including the step of assigning a value of 10 to A, a value of 13 to B, and a value of 20 to C.

14. The method as set forth in claim 1, further including the step of utilizing the fuel trim PID data, as assigned to the different ones of the cells, to flag probable cause(s) of one or more Power Plant problems.

15. The method as set forth in claim 1, wherein the step of assigning fuel trim PID data to different ones of the cells further includes the step of also assigning the associated fuel trim value and its positive or negative character.

16. The method as set forth in claim 1, wherein the instrumentation also includes a display screen, and further including the step of displaying the fuel trim PID data assigned to different cells on the display screen.

17. The method as set forth in claim 16, further including the steps of dividing possible fuel trim values into a series of ranges and assigning to each range of fuel trim values a distinct code.

18. The method as set forth in claim 17, wherein the step of assigning distinct codes includes the step of assigning a different color to each distinct code.

19. The method as set forth in claim 1, wherein programming the microprocessor to determine engine speed includes programming the microprocessor to extract PID data that provides information on the speed of the engine (hereinafter “

engine speed PID data”

), and wherein the step of determining engine speed includes the step of acquiring engine speed PID data from the powertrain control module with the instrumentation while the engine speed is changing.

20. The method as set forth in claim 19, wherein programming the microprocessor to extract engine speed PID data includes programming the microprocessor to extract RPM PID data, and the step of acquiring engine speed PID data includes the step of acquiring engine RPM PID data.

21. The method as set forth in claim 19, wherein the programming of the microprocessor to extract engine speed PID data includes programming the microprocessor to extract PID data selected from the group including engine RPM PID data, Vehicle Speed Sensor PID data, and Time Since Engine Start PID data;

and wherein the step of acquiring engine speed PID data includes the step of acquiring at least one of engine RPM PID data, Vehicle Speed Sensor PID data, and Time Since Engine Start PID data.

22. The method as set forth in claim 1, wherein the steps of changing the engine speed and engine load takes the form of increasing the engine speed and increasing the engine load.

23. The method as set forth in claim 22, wherein the steps of increasing the engine speed and the engine load is achieved by driving the vehicle in which the engine is mounted.

24. A method of providing information on the operating condition of a Power Plant utilizing fuel trim data;

the Power Plant including an engine and a powertrain control module;

the method utilizing instrumentation including a microprocessor, a chart of absolute throttle position (hereinafter “

ATP”

) vs. engine speed (RPM), and a screen for displaying the chart;

the chart being divided into a number of cells, each cell representing a range of ATPs vs. engine speeds wherein no two cells have both the same range of ATPs and the same range of engine speeds;

the microprocessor being programmed to extract parameter identification data (hereinafter “

PID data”

) form the powertrain control module;

the method including the steps of;

a. acquiring PID data with the instrumentation, including RPM PID data, ATP PID data and fuel trim PID data, from the powertrain control module;

b. changing both the engine speed and the engine load;

c. assigning fuel trim PID data, as such data is acquired, to different ones of the cells as both the engine speed and ATP change; and

d. displaying the assigned fuel trim PID data on the screen.

25. An automotive diagnostic chart embodied on instrumentation including a microprocessor for providing information on the fuel delivery system of a Power Plant, the chart including a first axis representing increasing values of engine load, a second axis representing increasing values of engine speed, the chart further including a plurality of cells, each cell representing a different range of engine loads vs. engine speeds.

26. The chart as set forth in claim 25, wherein at least some of the cells can be used to present information relating to fuel trim.