DIAGNOSTIC SYSTEM AND METHOD FOR PROCESSING CONTINUOUS AND INTERMITTENT FAULTS

• US 20140025249A1
• Filed: 09/13/2012
• Published: 01/23/2014
• Est. Priority Date: 07/19/2012
• Status: Active Grant

• Current Assignee: GM Global Technology Operations LLC (General Motors Company)
• Original Assignee: GM Global Technology Operations LLC (General Motors Company)
• Inventors: GILES, Peter John, VAN GILDER, John F.
• Granted Patent: US 8,868,282 B2
• Time in Patent Office: Days
• US Class Current: 701/29.2
• CPC Class Codes: B60W 20/50 Control strategies for responding to system failures, e.g. for fault diagnosis, failsafe operation or limp mode
• CPC Class Codes: B60W 50/035 Bringing the control units into a predefined state, e.g. giving priority to particular actuators
• CPC Class Codes: G05B 23/0235 based on a comparison with predetermined threshold or range, e.g. "classical methods", carried out during normal operation; threshold adaptation or choice; when or how to compare with the threshold

Abstract

A method for diagnosing a device of a vehicle, includes: generating samples of a parameter of the device; indicating whether each of the samples passed or failed based on comparisons of the samples with one of a predetermined value and a predetermined range; tracking a first number of consecutive samples compared, a second number of the first number of samples that failed, a third number of the first number of samples that failed consecutively, and a fourth number of a last predetermined number of samples compared that failed; selecting one of a normal control mode, a temporary default action mode and a permanent default action mode based on the first, second, third, and fourth numbers; and selectively setting a diagnostic trouble code (DTC) in memory when in the permanent default action mode.

Claims

1. A diagnostic system for diagnosing a device of a vehicle, comprising:

a sampling module that generates samples of a parameter of the device;

a diagnostic control module that indicates whether each of the samples passed or failed based on comparisons of the samples with one of a predetermined value and a predetermined range;

a counter module that tracks a first number of consecutive samples compared, that tracks a second number of the first number of samples that failed, that tracks a third number of the first number of samples that failed consecutively, and that tracks a fourth number of a last predetermined number of samples compared that failed,

wherein the diagnostic control module further;

selects one of a normal control mode, a temporary default action mode and a permanent default action mode based on the first, second, third, and fourth numbers;

transitions from the normal control mode to the temporary default action mode and takes a temporary default action based on at least one of the third and fourth numbers;

transitions to the permanent default action mode and takes a permanent default action based on at least one of the first, third, and fourth numbers; and

selectively sets a diagnostic trouble code (DTC) in memory when in the permanent default action mode.

2. The diagnostic system of claim 1 further comprising a malfunction indicator lamp (MIL) that illuminates when the DTC is set.

3. The diagnostic system of claim 1 wherein the permanent default action is different than the temporary default action.

4. The diagnostic system of claim 1 wherein:

the counter module further tracks a period of operation in the temporary default action mode; and

the diagnostic control module transitions to the permanent default action mode and takes the permanent default action in response to a determination that the period is greater than a predetermined period.

5. The diagnostic system of claim 1 wherein:

the counter module further tracks a fifth number of transitions from the normal control mode to the temporary default action mode; and

the diagnostic control module transitions to the permanent default action mode and takes the permanent default action in response to a determination that the fifth number is greater than a predetermined value.

6. The diagnostic system of claim 1 wherein the diagnostic control module transitions to the permanent default action mode and takes the permanent default action in response to a determination that the second number is greater than a predetermined value.

7. The diagnostic system of claim 1 wherein:

the counter module further tracks a period of operation in the temporary default action mode and tracks a fifth number of transitions from the normal control mode to the temporary default action mode; and

the diagnostic control module transitions to the permanent default action mode and takes the permanent default action in response to;

a first determination that the period is greater than a predetermined period;

a second determination that the fifth number is greater than a first predetermined value; and

a third determination that that the second number is greater than a second predetermined value.

8. The diagnostic system of claim 1 wherein the diagnostic control module transitions to the temporary default action mode and takes the temporary default action in response to a determination that the third number is greater than a predetermined value.

9. The diagnostic system of claim 8 wherein the diagnostic control module transitions to the temporary default action mode and takes the temporary default action further in response to a second determination that the fourth number is greater than a second predetermined value.

10. The diagnostic system of claim 8 wherein:

the counter module further tracks a fifth number of samples compared since a last failed sample; and

the diagnostic control module transitions from the temporary default action mode to the normal control mode in response to a third determination that both;

the fifth number is greater than a third predetermined value; and

the fourth number is less than a fourth predetermined value.

11. A method for diagnosing a device of a vehicle, comprising:

generating samples of a parameter of the device;

indicating whether each of the samples passed or failed based on comparisons of the samples with one of a predetermined value and a predetermined range;

tracking a first number of consecutive samples compared, a second number of the first number of samples that failed, a third number of the first number of samples that failed consecutively, and a fourth number of a last predetermined number of samples compared that failed;

selecting one of a normal control mode, a temporary default action mode and a permanent default action mode based on the first, second, third, and fourth numbers;

transitioning from the normal control mode to the temporary default action mode and taking a temporary default action based on at least one of the third and fourth numbers;

transitioning to the permanent default action mode and taking a permanent default action based on at least one of the first, third, and fourth numbers; and

selectively setting a diagnostic trouble code (DTC) in memory when in the permanent default action mode.

12. The method of claim 11 further comprising illuminating a malfunction indicator lamp (MIL) when the DTC is set.

13. The method of claim 11 wherein the permanent default action is different than the temporary default action.

14. The method of claim 11 further comprising:

tracking a period of operation in the temporary default action mode; and

transitioning to the permanent default action mode and taking the permanent default action in response to a determination that the period is greater than a predetermined period.

15. The method of claim 11 further comprising:

tracking a fifth number of transitions from the normal control mode to the temporary default action mode; and

transitioning to the permanent default action mode and taking the permanent default action in response to a determination that the fifth number is greater than a predetermined value.

16. The method of claim 11 further comprising transitioning to the permanent default action mode and taking the permanent default action in response to a determination that the second number is greater than a predetermined value.

17. The method of claim 11 further comprising:

tracking a period of operation in the temporary default action mode;

tracking a fifth number of transitions from the normal control mode to the temporary default action mode; and

transitioning to the permanent default action mode and taking the permanent default action in response to;

a first determination that the period is greater than a predetermined period;

a second determination that the fifth number is greater than a first predetermined value; and

a third determination that that the second number is greater than a second predetermined value.

18. The method of claim 11 further comprising transitioning to the temporary default action mode and taking the temporary default action in response to a determination that the third number is greater than a predetermined value.

19. The method of claim 18 further comprising transitioning to the temporary default action mode and taking the temporary default action further in response to a second determination that the fourth number is greater than a second predetermined value.

20. The method of claim 18 further comprising:

tracking a fifth number of samples compared since a last failed sample; and

transitioning from the temporary default action mode to the normal control mode in response to a third determination that both;

the fifth number is greater than a third predetermined value; and

the fourth number is less than a fourth predetermined value.