Fault identification diagnostic for intake system sensors

• US 6,701,282 B2
• Filed: 09/20/2001
• Issued: 03/02/2004
• Est. Priority Date: 09/20/2001
• Status: Active Grant

• Current Assignee: GM Global Technology Operations LLC (General Motors Company)
• Original Assignee: General Motors Corporation (Motors Liquidation Co. GUC Trust)
• Inventors: Van Gilder, John F., Ting, Thomas L.
• Primary Examiner(s): Hoff, Marc S.
• Assistant Examiner(s): SUAREZ, FELIX E
• Application Number:
  US09/961,537
• Publication Number:
  US 20030065483A1
• Time in Patent Office: 894 Days
• Field of Search: 702/45, 702/47, 702/138, 702/183, 702/185, 701/36, 123/525, 731/173
• US Class Current: 702/185
• CPC Class Codes: F02D 11/107 Safety-related aspects
• CPC Class Codes: F02D 2200/0402 the parameter being determined by using a model of the engine intake or its components
• CPC Class Codes: F02D 2200/0404 Throttle position
• CPC Class Codes: F02D 2200/0406 Intake manifold pressure
• CPC Class Codes: F02D 2200/704 Estimation of atmospheric pressure
• CPC Class Codes: F02D 41/1401 characterised by the control or regulation method F02D41/1473, F02D41/1477 take precedence
• CPC Class Codes: F02D 41/187 using a hot wire flow sensor
• CPC Class Codes: F02D 41/22 Safety or indicating devices for abnormal conditions in air/fuel ratio feedback systems F02D41/1495, in electric control linkage F02D11/107, in purge control systems F02M25/0809
• CPC Class Codes: Y02T 10/40 Engine management systems

Abstract

A fault identification system for intake system sensors according to the invention includes a throttle position sensor (TPS), a manifold absolute pressure (MAP) sensor, and a mass airflow (MAF) sensor. A diagnostic controller is coupled to the TPS, the MAP sensor and the MAF sensor. The diagnostic controller implements a throttle model, a first intake model and a second intake model and correctly identifies faults in the TPS, the MAP sensor and the MAF sensor. The throttle model generates a mass airflow estimate. The first intake model generates a first MAP estimate. The second intake model generates a second MAP estimate. The diagnostic controller applies residual calculations on outputs of the throttle model, the first intake model and the second intake model. The diagnostic controller applies a first order lag filter on the residual calculations. The diagnostic controller accesses a truth table to identify faults in the TPS, the MAP sensor and the MAF sensor.

Claims

1. A fault identification system for intake system sensors, comprising:

a throttle position sensor (TPS);

a manifold absolute pressure (MAP) sensor;

a mass airflow (MAF) sensor; and

a diagnostic controller that is coupled to said TPS, said MAP sensor and said MAF sensor, that implements a throttle model, a first intake model and a second intake model, and that identifies a fault in one of said TPS, said MAP sensor and said MAF sensor.

2. The fault identification system of claim 1 wherein said throttle model generates a mass airflow estimate.

3. The fault identification system of claim 2 wherein said first intake model generates a first MAP estimate.

4. The fault identification system of claim 3 wherein said second intake model generates a second MAP estimate.

5. The fault identification system of claim 4 wherein said diagnostic controller performs residual calculations on outputs of said throttle model, said first intake model and said second intake model.

6. The fault identification system of claim 5 wherein said diagnostic controller performs a first order lag filter on said residual calculations.

7. The fault identification system of claim 6 wherein said diagnostic controller employs a truth table to identify faults in said TPS, said MAP sensor and said MAF sensor.

8. A fault identification method for intake system sensors, comprising the steps of:

generating a mass airflow estimate using a throttle model;

generating a first manifold absolute pressure (MAP) estimate using a first intake model;

generating a second MAP estimate using a second intake model; and

identifying faults in one of a throttle position sensor (TPS), a mass airflow (MAF) sensor and a manifold absolute pressure (MAP) sensor using said MAF estimate, said first MAP estimate and said second MAP estimate.

9. The fault identification method of claim 8 further comprising the step of performing residual calculations on said MAF estimate, said first MAP estimate and said second MAP estimate.

10. The fault identification method of claim 9 further comprising the step of performing a first order lag filter calculations on said residual calculations.

11. The fault identification method of claim 10 further comprising the step of employing a truth table on said first order lag filter calculations to identify faults in said TPS, said MAP sensor and said MAF sensor.

12. A fault identification system for intake system sensors, comprising:

a throttle position sensor (TPS);

a manifold absolute pressure (MAP) sensor;

a mass airflow (MAF) sensor;

a diagnostic controller that is coupled to said TPS, said MAP sensor, and said MAF sensor, that includes a throttle module, a first intake module, a second intake module and a filter module, and that identifies a fault in one of said TPS, said MAP sensor and said MAF sensor.

13. The fault identification system of claim 12 wherein said throttle module generates a mass airflow estimate.

14. The fault identification system of claim 13 wherein said first intake module generates a first mass airflow estimate.

15. The fault identification system of claim 14 wherein said second intake module generates a second mass airflow estimate.

16. The fault identification system of claim 15 wherein said filter module performs residual calculations on outputs of said throttle module, said first intake module and said second intake module.

17. The fault identification system of claim 16 wherein said filter module performs a first order lag filter on said residual calculations.

18. The fault identification system of claim 17 wherein said filter module employs a truth table to identify faults in said TPS, MAP and MAF sensors.