AUXILIARY PUMP DIAGNOSTIC SYSTEMS AND METHODS

• US 20100217470A1
• Filed: 02/25/2009
• Published: 08/26/2010
• Est. Priority Date: 02/25/2009
• Status: Active Grant

• Current Assignee: GM Global Technology Operations LLC (General Motors Company)
• Original Assignee: GM Global Technology Operations Incorporated (General Motors Company)
• Inventors: Porto, Brian M., Chernyak, Michael, Polom, Michael E., Rademacher, Roger Joseph, Aldrich, William L. III, Tarnowsky, Steven A., Van Maanen, Keith D., Crites, Donald D.
• Granted Patent: US 8,116,932 B2
• Time in Patent Office: Days
• US Class Current: 701/29
• CPC Class Codes: F04B 17/05 driven by internal-combustion engines
• CPC Class Codes: F04B 51/00 Testing machines, pumps, or pumping installations

Abstract

An auxiliary pump diagnostic system includes a slip determination module and a fault determination module. The slip determination module determines slip of a torque converter based on an engine speed and a transmission input speed. The fault determination module diagnoses a fault in an auxiliary pump based on the slip of the torque converter.

Claims

1. An auxiliary pump diagnostic system comprising:

a slip determination module that determines slip of a torque converter based on an engine speed and a transmission input speed; and

a fault determination module that diagnoses a fault in an auxiliary pump based on the slip of the torque converter.

2. The auxiliary pump diagnostic system of claim 1 further comprising an enablement module that enables the fault determination module after the engine auto-start and before a mechanical pump establishes a threshold pressure in the torque converter.

3. The auxiliary pump diagnostic system of claim 2 wherein the enablement module enables the fault determination module when the slip of the torque converter exceeds a first predetermined value.

4. The auxiliary pump diagnostic system of claim 3 wherein the fault determination module records a sample count when the slip of the torque converter exceeds the first predetermined value.

5. The auxiliary pump diagnostic system of claim 4 wherein the fault determination module records a fail count when a ratio of the slip to an engine speed is below a second predetermined value.

6. The auxiliary pump diagnostic system of claim 5 wherein the fault determination module diagnoses a fault in the auxiliary pump when the sample count reaches a third predetermined value and a ratio of the fail count to the sample count exceeds a fourth predetermined value.

7. The auxiliary pump diagnostic system of claim 1 further comprising a driver input evaluation module that determines the status of driver input devices.

8. The auxiliary pump diagnostic system of claim 7 wherein a diagnosis is aborted when the driver input evaluation module determines a changed status of driver input devices.

9. The auxiliary pump diagnostic system of claim 8 wherein the changed status includes shifting of a drive selector.

10. The auxiliary pump diagnostic system of claim 8 wherein the changed status includes a vehicle speed increase exceeding a second threshold rate.

11. A method of diagnosing an auxiliary pump comprising:

determining slip of a torque converter; and

diagnosing an auxiliary pump based on the slip.

12. The method of claim 11 further comprising starting a diagnosis within a predetermined time period after engine auto-start and before a mechanical pump establishes a threshold pressure in the torque converter.

13. The method of claim 11 further comprising starting a diagnosis when the slip of the torque converter exceeds a first predetermined value.

14. The method of claim 13 further comprising recording a sample count when the slip of the torque converter exceeds the first predetermined value.

15. The method of claim 14 further comprising recording a fail count when a ratio of the slip to an engine speed is below a second predetermined value.

16. The method of claim 15 further comprising diagnosing a fault in the auxiliary pump when the sample count reaches a third predetermined value and a ratio of the fail count to the sample count exceeds a fourth predetermined value.

17. The method of claim 11 further comprising aborting the diagnosis when a changed status of driver inputs is detected.

18. The method of claim 17 wherein the changed status of driver input devices includes shifting of a gear selector.

19. The method of claim 11 further comprising aborting the diagnosis when the vehicle speed increases at a rate exceeding a threshold.