Hybrid vehicle fuel system leak detection
First Claim
Patent Images
1. A method for a vehicle with an engine, comprising:
- during an engine off condition,delivering fuel from a fuel tank into a reservoir while the fuel tank is vented to atmosphere;
discontinuing delivering fuel into the reservoir;
sealing the fuel tank from atmosphere; and
following the sealing, indicating a leak based on a pressure increase in the fuel tank from a pressure when sealed from venting.
1 Assignment
0 Petitions
Accused Products
Abstract
Methods and systems for fuel system leak detection in a hybrid electric vehicle using a fuel reservoir are disclosed. In one example approach, a method comprises, during an engine off condition, delivering fuel from a fuel tank into a reservoir while the fuel tank is vented to atmosphere, discontinuing delivering fuel into the reservoir, sealing the fuel tank from atmosphere, and following the sealing, indicating a leak based on a pressure increase in the fuel tank from a pressure when sealed from venting.
29 Citations
20 Claims
-
1. A method for a vehicle with an engine, comprising:
during an engine off condition, delivering fuel from a fuel tank into a reservoir while the fuel tank is vented to atmosphere; discontinuing delivering fuel into the reservoir; sealing the fuel tank from atmosphere; and following the sealing, indicating a leak based on a pressure increase in the fuel tank from a pressure when sealed from venting. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
-
10. A method for a vehicle with an engine with a fuel system, comprising:
-
during a first engine off condition, generating a pressure increase by delivering fuel from a fuel tank into a reservoir with the fuel tank vented to atmosphere and identifying leaks based on the pressure increase; and during a second engine off condition, generating vacuum by delivering fuel from the fuel tank into the reservoir with the fuel tank sealed from atmosphere and identifying leaks based on the generated vacuum. - View Dependent Claims (11, 12, 13, 14, 15, 16)
-
-
17. A vehicle system, comprising:
-
a fuel system including a fuel tank and a fuel vapor canister; a fuel reservoir; a fuel pump; a fuel tank isolation valve; and a controller including non-transitory instructions to; during a first engine off condition; open the fuel tank isolation valve and operate the fuel pump to deliver fuel from the fuel tank into the reservoir; close the fuel tank isolation valve and discontinue operation of the fuel pump; and indicate a leak based on a pressure increase in the fuel tank being less than a pressure increase threshold after operation of the fuel pump is discontinued; and during a second engine off condition; close the fuel tank isolation valve and operate the fuel pump to deliver fuel from the fuel tank into the reservoir; and discontinue operation of the fuel pump and indicate a leak based on a vacuum increase in the fuel tank being less than a vacuum increase threshold after operation of the fuel pump is discontinued. - View Dependent Claims (18, 19, 20)
-
Specification