System for processing output signals associated with multiple vehicle condition sensors

• US 5,880,674 A
• Filed: 05/12/1997
• Issued: 03/09/1999
• Est. Priority Date: 05/12/1997
• Status: Expired due to Term

• Current Assignee: Cummins Engine IP Inc (Cummins Incorporated)
• Original Assignee: Cummins Engine Company Incorporated (Cummins Incorporated)
• Inventors: Ufkes, Phi, Eckert, Gary
• Primary Examiner(s): Hofsass, Jeffery A.
• Assistant Examiner(s): TWEEL JR, JOHN ALEXANDER
• Application Number:
  US08/855,871
• Time in Patent Office: 666 Days
• Field of Search: 340/438, 340/450, 340/450.2, 340/459, 340/522, 340/441, 340/461
• US Class Current: 340/438
• CPC Class Codes: B60R 16/0232 for measuring vehicle parameters and indicating critical, abnormal or dangerous conditions
• CPC Class Codes: F02D 33/003 Controlling the feeding of liquid fuel from storage containers to carburettors or fuel-injection apparatus control of electrical fuel pumps F02D41/3082, controlling fuel flow to a common rail F02D41/3845; Failure or leakage prevention; Diagnosis or detection of failure; Arrangement of sensors in the fuel system; Electric wiring; Electrostatic discharge

Abstract

A system for processing output signals associated with multiple vehicle condition sensors includes a first sensor producing a pair of output signals indicative of a first vehicle condition and a second sensor producing an output signal indicative of a second vehicle condition. One of the first sensor output signals and the second sensor output signal are received by an interface circuit which produces an output signal that is a function of its two input signals. A vehicle control computer receives the output of the interface circuit and the other of the first sensor output signals and processes these signals to provide diagnostic information related to each of the two sensors. The diagnostic information may include fault codes associated with individual ones, or a combination, of the two sensors which are stored in memory, and may further include energizing signals for energizing warning means associated with each of the two sensors.

Claims

1. A system for processing output signals associated with multiple vehicle condition sensors comprising:

means for sensing a first vehicle condition and producing first and second output signals corresponding thereto;

means for sensing a second vehicle condition and producing a third output signal corresponding thereto;

means for combining said first and third output signals into a fourth output signal that is a simultaneous function of said first and third output signals; and

means responsive to said second and fourth output signals for producing diagnostic information associated with said first and second vehicle conditions.

2. The system of claim 1 wherein said first and second output signals are redundant output signals.

3. The system of claim 2 wherein said first and second redundant output signals are complementary output signals.

4. The system of claim 1 wherein said first vehicle condition corresponds to engine coolant level;

and wherein each of said first and second output signals define first and second states respectively when engine coolant level is below a predefined engine coolant level, and define third and fourth opposite states respectively when engine coolant level exceeds said predefined engine coolant level.

5. The system of claim 4 wherein said second vehicle condition sensor corresponds to water-in-fuel;

and wherein said third output signal defines a fifth state when water-in-fuel is below a predefined water-in-fuel level, and defines a sixth opposite state when water-in-fuel exceeds said predefined water-in-fuel level.

6. The system of claim 1 wherein said diagnostic information associated with said first and second vehicle conditions includes fault conditions associated therewith;

and further including means responsive to a first fault condition associated with said first vehicle condition for warning a vehicle operator thereof.

7. The system of claim 6 further including means responsive to a second fault condition associated with said second vehicle condition for warning a vehicle operator thereof.

8. The system of claim 1 wherein said diagnostic information associated with said first and second vehicle conditions includes fault conditions associated therewith;

and further including means responsive to a first fault condition associated with said first vehicle condition for storing a first fault code corresponding thereto.

9. The system of claim 8 wherein said means responsive to said first fault condition is further responsive to a second fault condition associated with said second vehicle condition for storing a second fault code corresponding thereto.

10. The system of claim 9 wherein said means responsive to said first fault condition is further responsive to said first and second fault conditions for storing a third fault code corresponding to a simultaneous occurrence of said first and second fault conditions.

11. A system for processing output signals associated with multiple vehicle condition sensors comprising:

a first sensor sensing a first vehicle condition and producing first and second output signals corresponding thereto;

a second sensor sensing a second vehicle condition and producing a third output signal corresponding thereto;

an interface circuit having a first input receiving said first output signal and a second input receiving said third output signal, said interface circuit combining said first and third signals into a fourth output signal that is a simultaneous function of said first and third output signals; and

a processor having a first input receiving said second output signal and a second input receiving said fourth output signal, said processor responsive to said second and fourth output signals to produce diagnostic information associated with said first and second sensors.

12. The system of claim 11 wherein said first and second output signals are redundant output signals.

13. The system of claim 12 wherein said first and second redundant output signals are complementary output signals.

14. The system of claim 11 wherein said first sensor is an engine coolant level sensor;

wherein said second sensor is a water-in-fuel sensor.

15. The system of claim 14 further including a fuel filter assembly operable to separate water from fuel and collect the separated water in a filter chamber;

wherein said water-in-fuel sensor includes a pair of conductive probes extending upwardly into said filter chamber;

and wherein said third output signal defines an inactive state thereof when the separated water in said filter chamber is below a level sufficient to permit conduction of electrical current between said conductive probes, and defines an active state thereof when the separated water in said filter chamber exceeds said level to thereby permit conduction of electrical current between said conductive probes.

16. The system of claim 15 wherein said water-in-fuel sensor includes an electrically insulating body formed about a portion of said conductive probes, said insulating body having one end thereof in contact with a bottom of said filter chamber and an opposite end extending upwardly into said filter chamber, said conductive probes protruding from said opposite end of said insulating body to thereby define said water level sufficient to permit conduction of electrical current therebetween.

17. The system of claim 15 wherein each of said conductive probes are separately electrically insulated along a portion thereof from a bottom of said filter chamber to thereby define said water level sufficient to permit conduction of electrical current therebetween.

18. The system of claim 11 wherein said diagnostic information associated with said first and second sensors includes fault conditions associated with said first and second vehicle conditions respectively;

and further including means responsive to a first fault condition associated with said first vehicle condition for warning a vehicle operator thereof.

19. The system of claim 18 further including means responsive to a second fault condition associated with said second vehicle condition for warning a vehicle operator thereof.

20. The system of claim 11 wherein said diagnostic information associated with said first and second sensors includes fault conditions associated with said first and second vehicle conditions respectively;

and wherein said processor further includes a memory for storing a first fault code corresponding to a first fault condition associated with said first vehicle condition, a second fault code corresponding to a second fault condition associated with said second vehicle condition and a third fault code corresponding to a simultaneous occurrence of said first and second fault conditions.

21. A system for processing output signals associated with multiple vehicle condition sensors comprising:

a first sensor sensing a first vehicle condition and producing first and second output signals corresponding thereto;

a second sensor sensing a second vehicle condition and producing a third output signal corresponding thereto;

an interface circuit having a first input receiving said first output signal and a second input receiving said third output signal, said interface circuit producing a fourth output signal having the same state as said first output signal when said third output signal is in a first state and being inversely related to said first output signal when said third output signal is in a second state; and

a processor having a first input receiving said second output signal and a second input receiving said fourth output signal, said processor responsive to said second and fourth output signals to produce diagnostic information associated with said first and second sensors.

22. The system of claim 21 wherein said first and second output signals are redundant output signals.

23. The system of claim 22 wherein said first and second redundant output signals are complementary output signals.

24. The system of claim 21 wherein said first sensor is an engine coolant level sensor;

and

wherein said second sensor is a water-in-fuel sensor.

25. The system of claim 24 further including a fuel filter assembly operable to separate water from fuel and collect the separated water in a filter chamber;

wherein said water-in-fuel sensor includes a pair of conductive probes extending upwardly into said filter chamber;

and wherein said third output signal defines an inactive state thereof when the separated water in said filter chamber is below a level sufficient to permit conduction of electrical current between said conductive probes, and defines an active state thereof when the separated water in said filter chamber exceeds said level to thereby permit conduction of electrical current between said conductive probes.

26. The system of claim 25 wherein said water-in-fuel sensor includes an electrically insulating body formed about a portion of said conductive probes, said insulating body having one end thereof in contact with a bottom of said filter chamber and an opposite end extending upwardly into said filter chamber, said conductive probes protruding from said opposite end of said insulating body to thereby define said water level sufficient to permit conduction of electrical current therebetween.

27. The system of claim 25 wherein each of said conductive probes are separately electrically insulated along a portion thereof from a bottom of said filter chamber to thereby define said water level sufficient to permit conduction of electrical current therebetween.

28. The system of claim 21 wherein said diagnostic information associated with said first and second sensors includes fault conditions associated with said first and second vehicle conditions respectively;

and further including means responsive to a first fault condition associated with said first vehicle condition for warning a vehicle operator thereof.

29. The system of claim 28 further including means responsive to a second fault condition associated with said second vehicle condition for warning a vehicle operator thereof.

30. The system of claim 21 wherein said diagnostic information associated with said first and second sensors includes fault conditions associated with said first and second vehicle conditions respectively;

and wherein said processor further includes a memory for storing a first fault code corresponding to a first fault condition associated with said first vehicle condition, a second fault code corresponding to a second fault condition associated with said second vehicle condition and a third fault code corresponding to a simultaneous occurrence of said first and second fault conditions.