Vehicle diagnostic tool—utilizing volumetric efficiency

• US 8,160,767 B1
• Filed: 11/23/2009
• Issued: 04/17/2012
• 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:
  US12/624,124
• Time in Patent Office: 876 Days
• Field of Search: None
• 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 determining with the aid of instrumentation including a microprocessor if there is a problem with one or more components of a Power Plant the Power Plant including an engine of known displacement, a powertrain control module, an exhaust system, and an air induction system including at least one sensor used to determine air flow through the engine;

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

PID data”

) from the powertrain control module;

the microprocessor also being programmed with an algorithm which permits the determination of the theoretical air flow through an engine based on extracted PID data the method including the steps of;

a. acquiring PID data from the powertrain control module with the instrumentation, the PID data including engine load PID data, engine speed PID data and at least one of manifold absolute pressure (hereinafter “

MAP”

) PID data and mass air flow (hereinafter “

MAS”

) PID data

b. determining the actual air flow (weight/unit of time) through the engine with PID data from the at least one sensor;

c. determining the engine'"'"'s volumetric efficiency based on the actual air flow through the engine as determined by using the at least one sensor;

d. determining with the algorithm the theoretical air flow through the engine;

e. calculating a theoretical volumetric efficiency based on the theoretical air flow; and

f. comparing the actual volumetric efficiency based on the actual air flow through the engine with the theoretical air flow through the engine.

2. The method as set forth in claim 1, wherein the microprocessor is programmed to determine the actual air flow through the engine with a speed density algorithm, wherein the step of acquiring PID data includes acquiring MAP PID data from the powertrain control module, and wherein the step of determining the actual air flow through the engine includes determining the actual air flow with the speed density algorithm and the MAP PID data.

3. The method as set forth in claim 2, wherein:

the step of acquiring PID data includes acquiring RPM PID data and Absolute Throttle Position (ATP) PID data from the powertrain control module;

further including the steps of (i) utilizing the known displacement of the engine, (ii) measuring the barometric pressure, (iii) measuring the air intake temperature; and

wherein the step of determining the actual air flow through the engine with the speed density algorithm utilizes the acquired RPM and ATP PID data, the engine displacement, the barometric pressure and the intake air temperature.

4. The method as set forth in claim 2, wherein the step of acquiring PID data includes acquiring RPM PID data and ATP PID data from the powertrain control module;

further including the steps of (i) utilizing the known displacement of the engine, (ii) measuring the barometric pressure, (iii) and measuring the air intake temperature; and

wherein the step of determining the theoretical air flow through the engine with the speed density algorithm utilizes the acquired RPM and ATP PID data, the engine displacement, the barometric pressure and the intake air temperature.

5. The method as set forth in claim 1, wherein the step of acquiring PID data includes the step of acquiring MAS PID data, and the step of determining the air flow through the engine is reading the MAS PID data with the instrumentation.

6. The method as set forth in claim 1, wherein the instrumentation includes a table of air flow through the engine vs. engine speed, the table divided into a number of cells, each cell representing a different range of air flow rates (weight/unit of time) vs. different range of engine speeds, and wherein the step of comparing the actual air flow through the engine with the theoretical air flow through the engine includes the step of determining the percentage difference between the actual air flow and the theoretical air flow at various air flow rates and engine speeds and of assigning such determined percentage difference to various cells in the table, depending on the engine speed and air flow rate at which such percentage difference was determined.

7. The method as set forth in claim 6, wherein the percentage differences between the volumetric efficiency and the calculated theoretical volumetric efficiency constitute a range of values, and further including the step of dividing such range into a series of sub-ranges, and assigning each sub-range a distinct code.

8. The method as set forth in claim 7, wherein the step of assigning codes includes the step of assigning a different color to each of the sub-ranges.

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

A and +A.

10. The method as set forth in claim 9, further including the step of providing a second code for values between −

A and −

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

11. The method as set forth in claim 10, further including the step of providing a third code for values between −

B and −

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

12. The method as set forth in claim 11, further including the step of providing a fourth code for values greater than +C and less than −

C.

13. The method as set forth in claim 12, further including the step of assigning a first color to the range −

A to +A, assigning a second color to the range −

A to −

B and +A to +B, assigning a third color to the range −

B to −

C and +B to +C, and assigning a fourth color to values greater than C and less than C.

14. The method as set forth in claim 13, further including the step of assigning green as the first color and assigning red as the fourth color.

15. The method as set forth in claim 14, further including the step of assigning a value of 10 to A, a value of 13 to B, and a value of 16 to C.

16. The method as set forth in claim 15, further including the step of also assigning to each cell which is coded the actual value and its positive or negative character.

17. The method as set forth in claim 1, wherein the steps are performed on a gasoline engine.

18. The method as set forth in claim 1, wherein the steps are performed on a diesel engine.

19. A method of determining with the aid of instrumentation including a microprocessor if there is a problem with one or more of an engine, the exhaust system associated with such engine, or the sensor(s) used to read the actual air flow through such engine, the engine and sensor(s) connected to a powertrain control module, the microprocessor being programmed to extract parameter identification data (hereinafter “

PID data”

) from the powertrain control module, the microprocessor being programmed with an algorithm which permits the determination of the theoretical air flow through an engine based on extracted PID data, the microprocessor also being programmed to chart air flow through an engine (weight/unit of time) vs. time, the method comprising the steps of;

a. determining the air flow (weight/unit of time) through the engine with the at least one sensor;

b. determining the theoretical air flow through the engine (weight/unit of time) with the algorithm;

c.

d. graphing the actual air flow through the engine (weight/unit of time vs. time) as determined with the at least one sensor;

e. graphing the theoretical air flow through the engine (weight/unit of time vs. time); and

f. utilizing the graphs to aid in determining if there is a problem with one or more of the engine being tested, the exhaust system associated with such engine, or the sensor(s) used to read the air flow through such engine.

20. The method as set forth in claim 19, further including the step of superimposing one of the graph the air flow through the engine and the graph of theoretical air flow through the engine over the other of the graph of the air flow through the engine and the graph of theoretical air flow through the engine.

21. An automotive diagnostic table embodied on instrumentation including a microprocessor for providing information on the volumetric efficiency of an engine as the engine is running at various speeds, air flow data is being collected, and diagnostic instrumentation is determining the difference between actual air flow through the engine and theoretical air flow through the engine, the table including a first axis representing increasing values of mass air flow (weight/unit of time), a second axis representing increasing values of engine speed (RPM), the table further including a plurality of cells, each cell representing a different range of mass air flow vs. RPM.