Methods and systems for diagnosing degradation in pressureless fuel tank
AssigneeFord Global Technologies, LLC
InventorAed Dudar
Life of this patent
Estimating the term…
Abstract
Methods and systems are provided for diagnosing leaks/degradation in a fuel system. In one example, a system for a vehicle may comprise a variable volume device disposed within a fuel tank; an atmospheric port of the variable volume device fluidly coupled to a vent line upstream of a hydrocarbon sensor housed in the vent line, the vent line coupling a fuel vapor canister to atmosphere; and a controller storing instructions for monitoring output of the hydrocarbon sensor; and generating an indication of a degradation in the variable volume device based on the monitored hydrocarbon sensor. In this way, it is possible to effectively detect a degradation/leak in the variable volume device with minimal specialized components in the fuel system.
Claims20
A system for a vehicle, comprising:
- a variable volume device disposed within a fuel tank;
- an atmospheric port of the variable volume device fluidly coupled to a vent line upstream of a hydrocarbon sensor coupled to the vent line, the vent line coupling a fuel vapor canister to atmosphere;
- and
- a controller storing instructions for:
- monitoring output of the hydrocarbon sensor;
- and
- generating an indication of a degradation in the variable volume device based on the monitored hydrocarbon sensor.
A diagnostic method for a vehicle, the method comprising:
- monitoring a level of fuel in a fuel tank, the fuel tank including a bellows internal to the fuel tank, an atmospheric port of the bellows coupled to a vent line via a vapor line;
- isolating a refueling canister fluidly coupled to the fuel tank from a hydrocarbon sensor positioned in a vent line coupling the refueling canister to atmosphere by closing a changeover valve;
- activating a fuel pump positioned in the fuel tank to generate fuel vapors;
- and
- monitoring output of a hydrocarbon sensor coupled to the vent line to identify a degradation in the bellows.
A method for diagnosing a fuel system of a vehicle, the method comprising:
- during refueling of a fuel tank of the vehicle, monitoring a fuel level of the fuel tank, the fuel tank including a bellows, an atmospheric port of the bellows coupled to a vent line via a vapor line;
- monitoring a hydrocarbon sensor while the fuel level of the fuel tank increases during refueling, wherein the hydrocarbon sensor is positioned in the vent line proximal to an attachment point of the vent line and the vapor line;
- and
- identifying a degradation in the bellows coupled to the fuel tank based on the monitored hydrocarbon sensor.
Dependencies are inferred from the claim text.