Diagnostic system for catalytic converter using exhaust gas recirculation system that can detect exhaust pressure buildup

• US 6,968,833 B2
• Filed: 03/31/2004
• Issued: 11/29/2005
• Est. Priority Date: 03/31/2004
• Status: Active Grant

• Current Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Original Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Inventors: Yu, Songping, Cullen, Michael J., Gates, Freeman C.
• Primary Examiner(s): WOLFE JR, WILLIS RAY
• Application Number:
  US10/816,156
• Publication Number:
  US 20050217650A1
• Time in Patent Office: 608 Days
• Field of Search: 123/568.11, 123/568.16, 123/568.21, 701/102, 701/103, 701/108, 602/74, 602/76, 602/99, 603/11, 606/02, 606/052, 606/06, 181/230
• US Class Current: 123/568.16
• CPC Class Codes: F01N 11/002 the diagnostic devices measuring or estimating temperature or pressure in, or downstream of the exhaust apparatus
• CPC Class Codes: F02D 2200/0406 Intake manifold pressure
• CPC Class Codes: F02D 2200/0812 Particle filter loading
• CPC Class Codes: F02D 41/0055 Special engine operating conditions, e.g. for regeneration of exhaust gas treatment apparatus
• CPC Class Codes: F02D 41/029 the exhaust gas treating apparatus being a particulate filter
• CPC Class Codes: F02D 41/145 with determination means using an estimation
• CPC Class Codes: F02M 26/47 the characteristics being temperatures, pressures or flow rates
• CPC Class Codes: F02M 26/48 EGR valve position sensors details of the sensor installation in the valve housing F02M26/72
• CPC Class Codes: F02M 26/49 Detecting, diagnosing or indicating an abnormal function of the EGR system
• CPC Class Codes: F02M 26/61 in response to exhaust pressure
• CPC Class Codes: Y02T 10/40 Engine management systems

Abstract

A method is described for detecting exhaust pressure buildup in an engine'"'"'s exhaust system using information from an exhaust gas recirculation system having a valve.

Claims

1. A method for detecting pressure buildup in an exhaust passage of an internal combustion engine having an emission control device and an exhaust gas recirculation system with an exhaust valve, comprising:

moving the exhaust valve in the exhaust gas recirculation system to a preselected open position;

estimating exhaust pressure buildup based on manifold pressure and an indication of pressure in the exhaust gas recirculation system.

2. The method of claim 1 wherein said preselected open position is a substantially fully open position.

3. The method of claim 2 wherein said indication of pressure in the exhaust gas recirculation system includes a differential pressure across an orifice in the exhaust gas recirculation system.

4. The method of claim 3 wherein said orifice is upstream of the exhaust valve.

5. The method of claim 3 wherein said orifice is downstream of the exhaust valve.

6. The method of claim 1 wherein said manifold pressure is measured from a manifold pressure sensor.

7. The method of claim 1 wherein said manifold pressure is estimated from a mass air flow sensor.

8. The method of claim 1 wherein the emission control device is a three way catalyst.

9. The method of claim 1 wherein the emission control device is a particulate filter.

10. The method of claim 9 further comprising raising exhaust gas temperature to regenerate the particulate filter based on said estimated exhaust pressure buildup.

11. The method-of claim 1 further comprising taking default action in response to said estimated exhaust pressure buildup.

12. A system for an internal combustion engine, comprising:

an emission control device in an exhaust passage of the engine;

an exhaust gas recirculation system with an exhaust valve coupled between an intake and exhaust manifold of the engine, the exhaust gas recirculation system having at least a valve, an orifice, and a pressure sensor providing at least a partial indication of differential pressure across said orifice; and

a computer readable storage medium having code for moving said exhaust valve in the exhaust gas recirculation system to a preselected open position; and

code for detecting exhaust pressure buildup based on said pressure sensor and an indication of manifold pressure.

13. The system of claim 12 wherein said orifice is upstream of the valve.

14. The system of claim 12 wherein said orifice is downstream of the valve.

15. The system of claim 12 wherein said pressure sensor is a differential pressure sensor.

16. A system for an internal combustion engine, comprising:

an emission control device in an exhaust passage of the engine;

an intake manifold pressure sensor;

an exhaust gas recirculation system with an exhaust valve coupled between an intake and exhaust manifold of the engine, the exhaust gas recirculation system having at least a valve, an orifice downstream of said valve, and a pressure sensor indicating pressure between said valve and said orifice; and

a computer readable storage medium having code for moving said exhaust valve in the exhaust gas recirculation system to a preselected open position; and

code for detecting exhaust pressure buildup based on said intake manifold pressure sensor and said exhaust gas recirculation system pressure sensor.

17. The system of claim 16 wherein said emission control device is a particulate filter.

18. The system of claim 16 wherein said computer readable storage medium code for moving said exhaust valve in the exhaust gas recirculation system to said preselected open position includes moving said valve to a substantially fully open position.

19. The system of claim 18 wherein said computer readable storage medium further comprises code for moving said exhaust valve to said substantially fully open position under a selected air amount conditions.

20. The system of claim 16 wherein said intake manifold pressure sensor is an absolute pressure sensor.

21. A method for detecting pressure buildup in an exhaust passage of an internal combustion engine having an emission control device and an exhaust gas recirculation system with an exhaust valve and a sensor, comprising:

detecting exhaust pressure buildup based on information from the sensor in the exhaust gas recirculation system.

22. The method of claim 21 further comprising performing said detection while said valve is located in an open position.

23. The method of claim 22 said open position is a substantially fully open position.

24. The method of claim 23 where the exhaust gas recirculation system further comprises an orifice, wherein said orifice is upstream of the exhaust valve.

25. The method of claim 23 where the exhaust gas recirculation system further comprises an orifice, wherein said orifice is downstream of the exhaust valve.

26. The method of claim 21 wherein the emission control device is a three way catalyst.

27. The method of claim 21 wherein the emission control device is a particulate filter.