METHOD FOR OPERATING AN ENGINE CONTROL MODULE UNDER LOW VOLTAGE CONDITIONS

• US 20080228337A1
• Filed: 03/14/2007
• Published: 09/18/2008
• Est. Priority Date: 03/14/2007
• Status: Active Grant

• Current Assignee: GM Global Technology Operations LLC (General Motors Company)
• Original Assignee: GM Global Technology Operations LLC (General Motors Company)
• Inventors: Bolstrum, Daniel G., Bauerle, Paul A., Stempnik, Joseph M., Jess, Richard B., Worthing, James L., Storch, Sharon L.
• Granted Patent: US 8,046,128 B2
• Time in Patent Office: Days
• US Class Current: 701/29
• CPC Class Codes: F02D 11/107 Safety-related aspects
• CPC Class Codes: F02D 41/062 for starting F02D41/061 takes precedence
• 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 41/266 the computer being backed-up or assisted by another circuit, e.g. analogue

Abstract

A fault clearing system and method for an engine control system includes a plurality of processor modules to control and monitor the engine and set a plurality of faults. The plurality of processor modules includes an electronic throttle control (ETC) module to control and monitor a throttle of the engine, and a plurality of engine sensors and ETC sensors. An ETC diagnostic module monitors the ETC sensors and engine sensors, with the ETC diagnostic module setting a low voltage induced fault. The ETC diagnostic module will also enter one of a plurality of low voltage states in response to the low voltage induced fault. The ETC diagnostic module selectively controls the ETC module and selectively clears the faults in the ETC module and plurality of processor modules upon entry into one of the low voltage states.

Claims

1. A fault clearing system for an engine control system, comprising:

a plurality of processor modules operable to control and monitor said engine including an electronic throttle control (ETC) module operable to control and monitor a throttle of said engine, said processor modules setting faults based on outputs from a plurality of engine sensors and ETC sensors; and

an ETC diagnostic module that monitors said ETC sensors and said engine sensors, said ETC diagnostic module setting a low voltage induced fault, and entering one of a plurality of low voltage states in response to said low voltage induced fault, wherein said ETC diagnostic module controls said ETC module to selectively clear said faults in said ETC module and said plurality of processor modules upon entry into said one of said low voltage states.

2. The fault clearing system of claim 1 wherein said ETC diagnostic module performs within a processor controlled loop operable to periodically monitor said ETC faults, said ETC sensors and said engine sensors.

3. The fault clearing system of claim 1 wherein said plurality of low voltage states of said ETC diagnostic module includes a low power state selected by said ETC diagnostic module when a limited-power mode has already been selected by said ETC, wherein said low power state disables said fault clearing system and said ETC and said engine remain in said limited-power mode.

4. The fault clearing system of claim 3 wherein said plurality of low voltage states of said ETC diagnostic module includes a low voltage non-cranking state selected by said ETC diagnostic module when monitored voltages received from said engine and ETC sensors are less than a first calibration voltage.

5. The fault clearing system of claim 4 wherein said low voltage non-cranking state generates ETC diagnostic signals clearing low voltage induced faults for said ETC and said plurality of processor modules, and disables fuel to said engine.

6. The fault clearing system of claim 4 wherein said first calibration voltage is 6.0 V.

7. The fault clearing system of claim 3 wherein said plurality of low voltage states of said ETC diagnostic module includes a crank transition state selected by said ETC diagnostic module when:

monitored voltages received from said engine sensors and said ETC sensors are above a first calibration voltage for more than a first calibration time, so long as the ETC diagnostic module is not already in said low voltage non-cranking state;

monitored voltages received from said engine sensors and said ETC sensors are below a second calibration voltage;

monitored engine RPM is below a calibration RPM; and

the engine starter is currently cranking and has been cranking for less than a second calibration time.

8. The fault clearing system of claim 7 wherein said first calibration voltage is 6.0 V, said first calibration time is 225 milliseconds, said second calibration voltage is 30 V, said calibration RPM is 800 RPM, and said second calibration time is 15 seconds.

9. The fault clearing system of claim 7 wherein a first timer is started when said ETC diagnostic module receives voltages from said engine sensors and said ETC sensors that are greater than said first calibration voltage, wherein said ETC diagnostic module enters said crank transition state when said first timer is greater than said first calibration time.

10. The fault clearing system of claim 7 wherein a second timer is started when said engine starter begins cranking, wherein said ETC diagnostic module remains in said crank transition state until said second timer is greater than a second calibration time.

11. The fault clearing system of claim 7 wherein said crank transition state generates ETC diagnostic signals clearing low voltage faults for said ETC module and said plurality of processor modules, and enables said fuel to said engine.

12. The fault clearing system of claim 3 wherein said plurality of low voltage states includes a low voltage recovery state selected by said ETC diagnostics module when measured voltages received from said engine sensors and said ETC sensors are greater than a first calibration voltage for less than a first calibration time.

13. The fault clearing system of claim 12 wherein said first calibration voltage is 8.5 V and said first calibration time is 100 milliseconds.

14. The fault clearing system of claim 12 wherein a first timer is started when said ETC diagnostic module receives voltages from said engine sensors and said ETC sensors that are greater than said first calibration voltage.

15. The fault clearing system of claim 12 wherein said low voltage recovery state generates ETC diagnostic signals clearing low voltage faults for said ETC module and said plurality of processor modules and disables fuel to said engine, until said first timer is greater than said first calibration time, thereafter, said low voltage recovery state ends and said ETC diagnostic module returns to normal operation where none of said plurality of low voltage states are selected.

16. A method of clearing low voltage faults of an engine control system, comprising:

monitoring vehicle voltages and faults;

setting one of a plurality of low voltage states in response to a low voltage induced fault, wherein said low voltage states selectively control an electronic throttle control (ETC); and

selectively clearing said faults in said engine control system upon entry into said one of said low voltage states.

17. The method of claim 16 wherein said monitoring of vehicle voltages and faults is performed within a processor controlled periodic loop.

18. The method of claim 16 wherein said plurality of low voltage states includes a low power state selected when said ETC is already in a limited-power mode, wherein said low power state disables said low voltage fault clearing method and said ETC and said engine remain in said limited-power mode.

19. The method of claim 16 wherein said plurality of low voltage states includes a low voltage non-cranking state selected when monitored voltages are less than a first calibration voltage.

20. The method of claim 19 wherein said first calibration voltage is 5.5 V.

21. The method of claim 19 wherein said low voltage non-cranking state clears low voltage faults for said ETC and said engine;

and disables a fuel to said engine.

22. The method of claim 18 wherein said plurality of low voltage states includes a crank transition state, wherein said crank transition state is selected when:

monitored voltages are above a first calibration voltage for more than a first calibration time as long as a low voltage non-cranking state does not already exist;

monitored voltages are below a second calibration voltage;

monitored engine RPM is below a calibration RPM; and

an engine starter is currently cranking and has been cranking for less than a second calibration time.

23. The method of claim 22 wherein said first calibration voltage is 6.0 V, said first calibration time is 225 milliseconds, said second calibration voltage is 30 V, said calibration RPM is 800 RPM, and said second calibration time is 15 milliseconds.

24. The method of claim 23 wherein said crank transition state clears low voltage induced faults for said ETC system and said engine and enables said fuel to said engine.

25. The method of claim 16 wherein said plurality of low voltage states includes a low voltage recovery state that is selected when measured voltages are greater than a first calibration voltage for less than a first calibration time.

26. The method of claim 25 wherein said first calibration voltage is 8.5 V and said first calibration time is 100 milliseconds.

27. The method of claim 25 wherein said low voltage recovery state clears low voltage induced faults for said ETC system and said engine, and disables said fuel to said engine, until measured voltages are greater than said first calibration voltage for more than said first calibration time, thereafter, said low voltage recovery state ends and said low voltage fault clearing method returns to normal operation where none of said plurality of low voltage states are selected.