Manifold air flow (MAF) and manifold absolute pressure (MAP) residual electronic throttle control (ETC) security

• US 7,069,773 B2
• Filed: 04/23/2004
• Issued: 07/04/2006
• Est. Priority Date: 04/23/2004
• Status: Active Grant

• Current Assignee: GM Global Technology Operations LLC (General Motors Company)
• Original Assignee: General Motors Corporation (Motors Liquidation Co. GUC Trust)
• Inventors: Roberts, Colin A., Katrak, Kerfegar K., Bauerle, Paul A., Stempnik, Joseph M., Rogers, Bruce A.
• Primary Examiner(s): Lefkowitz, Edward
• Assistant Examiner(s): Kirkland, III, Freddie
• Application Number:
  US10/831,764
• Publication Number:
  US 20050235743A1
• Time in Patent Office: 802 Days
• Field of Search: 731/16, 731/172, 731/173, 731/181
• US Class Current: 73/114.32
• CPC Class Codes: F02D 11/105 characterised by the function converting demand to actuation, e.g. a map indicating relations between an accelerator pedal position and throttle valve opening or target engine torque
• 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 2200/0406 Intake manifold pressure
• CPC Class Codes: G01F 25/10 of flowmeters

Abstract

An engine fault diagnostic system includes a diagnostic module that generates a manifold absolute pressure (MAP) error signal and that generates a mass air flow (MAF) error signal. A security module generates an air flow fault when the MAP error signal exceeds a MAP threshold and the MAF error signal exceeds a MAF threshold.

Claims

1. An engine fault diagnostic system, comprising:

a diagnostic module that generates a manifold absolute pressure (MAP) error signal and that generates a mass air flow (MAF) error signal;

a security module that generates an air flow fault when said MAP error signal exceeds a MAP threshold and said MAF error signal exceeds a MAF threshold; and

a throttle position sensor that generates a throttle position signal, wherein said security module determines said MAP threshold and said MAF threshold based on said throttle position signal.

2. The engine fault diagnostic of claim 1 further comprising a MAP sensor that generates a MAP signal.

3. The engine fault diagnostic system of claim 2 wherein said MAP error signal is determined based on an estimated MAP and said MAP signal.

4. The engine fault diagnostic of claim 1 further comprising a MAF sensor that generates a MAF signal.

5. The engine fault diagnostic system of claim 4 wherein said MAF error signal is determined based on an estimated MAF and said MAF signal.

6. The engine fault diagnostic of claim 1 further comprising a throttle module that calculates an estimated MAF based on a MAP signal and a throttle position signal, wherein said MAF error signal is based on said estimated MAF and said MAF signal.

7. The engine fault diagnostic of claim 1 further comprising an intake module that calculates an estimated MAP based on a MAF signal and a throttle position signal, wherein said MAP error signal is based on said estimated MAP and said MAP signal.

8. A method of monitoring an air flow condition of an engine intake system, comprising:

determining a manifold absolute pressure (MAP) error;

determining a mass air flow (MAF) error;

generating an air flow fault when said MAP error exceeds a MAP threshold and said MAF error exceeds a MAF threshold; and

generating a throttle position signal using a throttle position sensor, wherein said MAP threshold and said MAF threshold are based on said throttle position signal.

9. The method of claim 8 further comprising generating a MAP signal using a MAP sensor, wherein said MAP error is determined based on an estimated MAP and said MAP signal.

10. The method of claim 8 further comprising generating a MAF signal using a MAF sensor, wherein said MAF error is determined based on an estimated MAF and said MAF signal.

11. The method of claim 8 further comprising calculating an estimated MAF based on a MAP signal and a throttle position signal, wherein said MAF error is based on said estimated MAF and said MAF signal.

12. The method of claim 8 further comprising calculating an estimated MAP based on a MAF signal and a throttle position signal, wherein said MAP error is based on said estimated MAP and said MAP signal.