METHOD AND SYSTEM FOR DETECTING A FAULT DURING CATALYST LIGHT-OFF

• US 20110106392A1
• Filed: 10/29/2009
• Published: 05/05/2011
• Est. Priority Date: 10/29/2009
• Status: Active Grant

• Current Assignee: GM Global Technology Operations LLC (General Motors Company)
• Original Assignee: GM Global Technology Operations Incorporated (General Motors Company)
• Inventors: VERNER, Douglas R., SANTOSO, Halim G., RAYL, Allen B., SHIBATA, Jonathan T., BUSLEPP, Kenneth J.
• Granted Patent: US 8,504,278 B2
• Time in Patent Office: Days
• US Class Current: 701/101
• CPC Class Codes: F01N 3/101 Three-way catalysts
• CPC Class Codes: F02D 41/0255 to accelerate the warming-up of the exhaust gas treating apparatus at engine start
• CPC Class Codes: F02D 41/1494 Control of sensor heater
• CPC Class Codes: F02D 41/1495 Detection of abnormalities in the air/fuel ratio feedback system
• 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: F02D 41/405 with post injections
• CPC Class Codes: Y02T 10/12 Improving ICE efficiencies

Abstract

A system and method for controlling engine operation includes a timer module that determines a time period from when a catalyst light-off mode is entered to when an oxygen sensor signal reaches an oxygen sensor threshold and a comparison module that generates an error signal and determines when the time period is above a time threshold.

Claims

1. A method of controlling engine operation, the method comprising:

entering a catalyst light-off mode;

initiating a timer in response to entering the catalyst light-off mode;

generating an oxygen sensor signal;

when the oxygen sensor signal reaches an oxygen sensor threshold, determining a time period from the timer; and

when the time period is above a time threshold, generating an error signal.

2. A method as recited in claim 1 further comprising when the time period is below the time threshold generating a no-fault signal.

3. A method as recited in claim 1 wherein generating an error signal comprises generating the error signal corresponding to a catalyst light-off mode error.

4. A method as recited in claim 1 wherein generating an error signal comprises generating the error signal corresponding to an oxygen sensor heater error.

5. A method as recited in claim 1 wherein after entering the catalyst light-off mode, providing split-pulse fuel injection into cylinders of the engine that comprise a first pulse and a second pulse.

6. A method as recited in claim 5 wherein generating an error signal comprises generating the error signal corresponding to a split-pulse error.

7. A method as recited in claim 5 wherein generating an error signal comprises generating the error signal corresponding to a missed second pulse.

8. A method as recited in claim 1 wherein generating an oxygen sensor signal comprises generating an oxygen sensor signal corresponding to a catalyst temperature.

9. A method as recited in claim 1 wherein generating an oxygen sensor signal comprises an oxygen sensor voltage signal.

10. A method as recited in claim 9 wherein the oxygen sensor voltage signal corresponds to an oxygen sensor impedance.

11. A system for controlling engine operation, comprising:

a timer module that determines a time period from when a catalyst light-off mode is entered to when an oxygen sensor signal reaches an oxygen sensor threshold; and

a comparison module that generates an error signal and determines when the time period is above a time threshold.

12. A system as recited in claim 11 wherein the comparison module generates a no-fault signal when the time period is below the time threshold.

13. A system as recited in claim 11 wherein the error signal corresponds to a catalyst light-off mode error.

14. A system as recited in claim 11 wherein the error signal corresponds to an oxygen sensor heater error.

15. A system as recited in claim 11 further comprising a catalyst light-off mode module that generates a split-pulse fuel injection into cylinders of the engine comprising a first pulse and a second pulse.

16. A system as recited in claim 15 wherein the error signal corresponds to a split-pulse error.

17. A system as recited in claim 15 wherein the error signal corresponds to a missed second pulse.

18. A system as recited in claim 11 wherein generating an oxygen sensor signal comprises generating an oxygen sensor signal corresponding to a catalyst temperature.

19. A system as recited in claim 11 wherein the oxygen sensor signal comprises an oxygen sensor voltage signal.

20. A system as recited in claim 19 wherein the oxygen sensor voltage signal corresponds to an oxygen sensor impedance.