Fuel vapor canister heater control and diagnostic systems and methods

• US 9,682,628 B2
• Filed: 01/23/2015
• Issued: 06/20/2017
• Est. Priority Date: 11/14/2014
• Status: Active Grant

• Current Assignee: GM Global Technology Operations LLC (General Motors Company)
• Original Assignee: GM Global Technology Operations LLC (General Motors Company)
• Inventors: Casetti, Martino, Cadman, William R., Burleigh, Darrell W.
• Primary Examiner(s): McMahon, Marguerite
• Assistant Examiner(s): HOLBROOK, TEUTA BAJRAMOVIC
• Application Number:
  US14/603,536
• Publication Number:
  US 20160138528A1
• Time in Patent Office: 879 Days
• Field of Search: 123518, 123519, 123520
• CPC Class Codes: B60L 7/26 Controlling the braking effect
• CPC Class Codes: B60W 10/00 Conjoint control of vehicle sub-units of different type or different function for propulsion of purely electrically-propelled vehicles with power supplied within the vehicle B60L50/00 - B60L58/00
• 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: F02M 2025/0881 with means to heat or cool the canister
• CPC Class Codes: F02M 25/0809 Judging failure of purge control system

Abstract

An energy module determines an amount of energy consumed by an electric heater of a fuel vapor canister since an ignition system of the vehicle was last transitioned from OFF to ON. A purge valve control module controls opening a purge valve while the ignition system of the vehicle is ON, wherein fuel vapor flows from the vapor canister through the purge valve to an air intake system when the purge valve is open. A heater control module selectively applies power to the electric heater of the fuel vapor canister and, based on at least one of the amount of energy consumed by the electric heater and a mass of fuel vapor that has flowed through the purge valve, selectively disconnects the electric heater from the power until after the ignition system is transitioned from ON to OFF.

Claims

1. A heater control system for a vehicle, comprising:

an energy module that determines an amount of energy consumed by an electric heater of a fuel vapor canister since an ignition system of the vehicle was last transitioned from OFF to ON;

a purge valve control module that controls opening a purge valve while the ignition system of the vehicle is ON, wherein fuel vapor flows from the vapor canister through the purge valve to an air intake system when the purge valve is open; and

a heater control module that selectively applies power to the electric heater of the fuel vapor canister and that, based on at least one of the amount of energy consumed by the electric heater and a mass of fuel vapor that has flowed through the purge valve, selectively disconnects the electric heater from the power until after the ignition system is transitioned from ON to OFF.

2. The heater control system of claim 1 wherein, when the amount of energy consumed by the electric heater is greater than a predetermined amount of energy, the heater control module disconnects the electric heater from the power until after the ignition system is transitioned from ON to OFF.

3. The heater control system of claim 1 wherein, when the mass of fuel vapor that has flowed through the purge valve is greater than a predetermined mass, the heater control module disconnects the electric heater from the power until after the ignition system is transitioned from ON to OFF.

4. The heater control system of claim 1 wherein, when both the amount of energy consumed by the electric heater is greater than a predetermined amount of energy and the mass of fuel vapor that has flowed through the purge valve is greater than a predetermined mass, the heater control module disconnects the electric heater from the power until after the ignition system is transitioned from ON to OFF.

5. The heater control system of claim 1 wherein the energy module determines the amount of energy consumed by the electric heater based on a voltage applied to the electric heater and a current through the electric heater.

6. The heater control system of claim 1 further comprising:

a conductance module that determines an electrical conductance of the electric heater; and

a fault module that selectively diagnoses a fault in the electric heater based on a maximum value of the electrical conductance determined between a first time when the power is applied to the electric heater and a second time when the power is disconnected from the electric heater.

7. The heater control system of claim 6 wherein the fault module diagnoses the fault in the electric heater when the maximum value of the electrical conductance is one of:

greater than a first predetermined conductance; and

less than a second predetermined conductance that is less than the first predetermined conductance.

8. The heater control system of claim 7 wherein the fault module diagnoses that the fault is not present in the electric heater when the maximum value of the electrical conductance is both:

less than the first predetermined conductance; and

greater than the second predetermined conductance.

9. The heater control system of claim 6 further comprising a monitoring module that illuminates a malfunction indicator lamp when the fault is diagnosed in the electric heater.

10. The heater control system of claim 6 wherein the fault module sets a predetermined diagnostic trouble code (DTC) associated with the fault in memory when the fault is diagnosed in the electric heater.

11. A heater control method for a vehicle, comprising:

determining an amount of energy consumed by an electric heater of a fuel vapor canister since an ignition system of the vehicle was last transitioned from OFF to ON;

controlling opening a purge valve while the ignition system of the vehicle is ON, wherein fuel vapor flows from the vapor canister through the purge valve to an air intake system when the purge valve is open;

selectively applying power to the electric heater of the fuel vapor canister; and

,

based on at least one of the amount of energy consumed by the electric heater and a mass of fuel vapor that has flowed through the purge valve, selectively disconnecting the electric heater from the power until after the ignition system is transitioned from ON to OFF.

12. The heater control method of claim 11 further comprising, when the amount of energy consumed by the electric heater is greater than a predetermined amount of energy, disconnecting the electric heater from the power until after the ignition system is transitioned from ON to OFF.

13. The heater control method of claim 11 further comprising, when the mass of fuel vapor that has flowed through the purge valve is greater than a predetermined mass, disconnecting the electric heater from the power until after the ignition system is transitioned from ON to OFF.

14. The heater control method of claim 11 further comprising, when both the amount of energy consumed by the electric heater is greater than a predetermined amount of energy and the mass of fuel vapor that has flowed through the purge valve is greater than a predetermined mass, disconnecting the electric heater from the power until after the ignition system is transitioned from ON to OFF.

15. The heater control method of claim 11 further comprising determining the amount of energy consumed by the electric heater based on a voltage applied to the electric heater and a current through the electric heater.

16. The heater control method of claim 11 further comprising:

determining an electrical conductance of the electric heater; and

selectively diagnosing a fault in the electric heater based on a maximum value of the electrical conductance determined between a first time when the power is applied to the electric heater and a second time when the power is disconnected from the electric heater.

17. The heater control method of claim 16 further comprising diagnosing the fault in the electric heater when the maximum value of the electrical conductance is one of:

greater than a first predetermined conductance; and

less than a second predetermined conductance that is less than the first predetermined conductance.

18. The heater control method of claim 17 further comprising diagnosing that the fault is not present in the electric heater when the maximum value of the electrical conductance is both:

less than the first predetermined conductance; and

greater than the second predetermined conductance.

19. The heater control method of claim 16 further comprising illuminating a malfunction indicator lamp when the fault is diagnosed in the electric heater.

20. The heater control method of claim 16 further comprising setting a predetermined diagnostic trouble code (DTC) associated with the fault in memory when the fault is diagnosed in the electric heater.