Purge valve detachment diagnostic systems and methods

• US 9,562,499 B2
• Filed: 11/12/2014
• Issued: 02/07/2017
• Est. Priority Date: 08/29/2014
• Status: Active Grant

• Current Assignee: GM Global Technology Operations LLC (General Motors Company)
• Original Assignee: GM Global Technology Operations LLC (General Motors Company)
• Inventors: Maxey, Miles K., Swartz, Kenneth C.
• Primary Examiner(s): Vo, Hieu T
• Application Number:
  US14/539,187
• Publication Number:
  US 20160061154A1
• Time in Patent Office: 818 Days
• US Class Current: 1/1
• CPC Class Codes: F02D 2041/225 Leakage detection
• CPC Class Codes: F02D 2200/0602 Fuel pressure
• CPC Class Codes: F02D 41/003 Adding fuel vapours, e.g. drawn from engine fuel reservoir
• CPC Class Codes: F02D 41/004 Control of the valve or purge actuator, e.g. duty cycle, closed loop control of position
• 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 41/221 relating to the failure of actuators or electrically driven elements
• CPC Class Codes: F02M 25/0818 having means for pressurising the evaporative emission space
• CPC Class Codes: F02M 25/0836 Arrangement of valves controlling the admission of fuel vapour to an engine, e.g. valve being disposed between fuel tank or absorption canister and intake manifold
• CPC Class Codes: Y02T 10/40 Engine management systems

Abstract

A diagnostic system for a vehicle includes a purge valve control module that closes a purge valve. The purge valve regulates fuel vapor flow from a fuel vapor canister to an intake system of an engine. A pump control module, after the closing of the purge valve, turns on a pump that pumps fuel vapor toward the purge valve. A first pressure module, after the purge valve is closed, determines a first pressure measured using a pressure sensor located between the pump and the purge valve. A second pressure module, after the determination of the first pressure and while the pump is on, determines a second pressure measured using the pressure sensor located between the pump and the purge valve. A diagnostic module selectively diagnoses detachment of the purge valve from the intake system based on the first and second pressures.

Claims

1. A diagnostic system for a vehicle, comprising:

a purge valve control module that closes a purge valve that regulates fuel vapor flow from a fuel vapor canister to an intake system of an engine;

a pump control module that, after the closing of the purge valve, turns on a pump that pumps fuel vapor toward the purge valve;

a first pressure module that, after the purge valve is closed, determines a first pressure measured using a pressure sensor located between the pump and the purge valve;

a second pressure module that, after the determination of the first pressure and while the pump is on, determines a second pressure measured using the pressure sensor located between the pump and the purge valve; and

a diagnostic module that selectively diagnoses detachment of the purge valve from the intake system based on the first and second pressures.

2. The diagnostic system of claim 1 further comprising a difference module that determines a pressure difference based on the second pressure minus the first pressure,

wherein the diagnostic module diagnoses the detachment of the purge valve when the pressure difference is less than a predetermined pressure.

3. The diagnostic system of claim 2 wherein the diagnostic module diagnoses attachment of the purge valve with the intake system when the pressure difference is greater than the predetermined pressure.

4. A system comprising:

the diagnostic system of claim 1; and

the purge valve, wherein the purge valve includes;

an input port that for receiving output from the pump; and

two output ports for sealingly engaging two input ports of the intake system, respectively.

5. The system of claim 4 wherein one of the two input ports of the intake system is closed to prevent flow from the purge valve into the intake system through the one of the two input ports.

6. The diagnostic system of claim 1 wherein the diagnostic module sets a predetermined diagnostic trouble code (DTC) in memory when the purge valve is detached from the intake system.

7. The diagnostic system of claim 1 further comprising a monitoring module that selectively illuminates a malfunction indicator lamp when the purge valve is detached from the intake system.

8. The diagnostic system of claim 1 wherein the second pressure module determines the second pressure a predetermined period after the determination of the first pressure.

9. The diagnostic system of claim 1 wherein the second pressure module determines the second pressure a predetermined period after the turning on of the pump.

10. The diagnostic system of claim 1 wherein the first pressure module determines the first pressure one of before and after the turning on of the pump.

11. A method comprising:

closing a purge valve that regulates fuel vapor flow from a fuel vapor canister to an intake system of an engine;

after the closing of the purge valve, turning on a pump that pumps fuel vapor toward the purge valve;

after the purge valve is closed, determining a first pressure measured using a pressure sensor located between the pump and the purge valve;

after the determination of the first pressure and while the pump is on, determining a second pressure measured using the pressure sensor located between the pump and the purge valve; and

selectively diagnosing detachment of the purge valve from the intake system based on the first and second pressures.

12. The method of claim 11 further comprising:

determining a pressure difference based on the second pressure minus the first pressure; and

diagnosing the detachment of the purge valve when the pressure difference is less than a predetermined pressure.

13. The method of claim 12 further comprising diagnosing attachment of the purge valve with the intake system when the pressure difference is greater than the predetermined pressure.

14. The method of claim 11 wherein the purge valve includes:

an input port that for receiving output from the pump; and

two output ports for sealingly engaging two input ports of the intake system, respectively.

15. The method of claim 14 wherein one of the two input ports of the intake system is closed to prevent flow from the purge valve into the intake system through the one of the two input ports.

16. The method of claim 11 further comprising setting a predetermined diagnostic trouble code (DTC) in memory when the purge valve is detached from the intake system.

17. The method of claim 11 further comprising selectively illuminating a malfunction indicator lamp when the purge valve is detached from the intake system.

18. The method of claim 11 further comprising determining the second pressure a predetermined period after the determination of the first pressure.

19. The method of claim 11 further comprising determining the second pressure a predetermined period after the turning on of the pump.

20. The method of claim 11 further comprising determining the first pressure one of before and after the turning on of the pump.