METHOD FOR DIAGNOSING A FUEL TANK VENT VALVE

• US 20150328980A1
• Filed: 05/13/2015
• Published: 11/19/2015
• Est. Priority Date: 05/13/2014
• Status: Active Grant

• Current Assignee: Robert Bosch GmbH
• Original Assignee: Robert Bosch GmbH
• Inventors: MEINKEN, Andreas, BRUESTLE, Simon, WIECZOREK, Thomas, KASTNER, Johannes, DEIBELE, Bernhard
• Granted Patent: US 9,945,330 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: B60K 15/03519 Valve arrangements in the vent line
• CPC Class Codes: B60K 2015/03328 Arrangements or special measures related to fuel tanks or fuel handling
• CPC Class Codes: F02M 25/0809 Judging failure of purge control system

Abstract

A method for diagnosing a fuel tank vent valve of a motor vehicle. In the method it is inferred, from a curve of a pressure p over time in a sub-chamber of the motor vehicle after a start-up of an internal combustion engine of the motor vehicle, as to whether the fuel tank vent valve is jammed open. The sub-chamber contains a fuel tank of the motor vehicle and is delimited by the fuel tank vent valve.

Claims

1. A method for diagnosing a fuel tank vent valve of a motor vehicle, comprising:

inferring, from a curve of a pressure p over time in a sub-chamber of the motor vehicle after a start-up of an internal combustion engine of the motor vehicle, as to whether a fuel tank vent valve is jammed open, the sub-chamber containing the fuel tank of the motor vehicle and being delimited by the fuel tank vent valve.

2. The method as recited in claim 1, wherein the sub-chamber includes:

the fuel tank,

an activated carbon filter of the motor vehicle,

a line which connects the fuel tank to the activated carbon filter, and

a line which connects the activated carbon filter to the fuel tank vent valve.

3. The method as recited in claim 1, wherein it is inferred that the fuel tank vent valve is jammed open if a drop in the pressure p in the sub-chamber takes place during a test period Δ

t after the start-up of the internal combustion engine.

4. The method as recited in claim 3, wherein no activation of the fuel tank vent valve takes place during the test period Δ

t.

5. The method as recited in claim 1, further comprising measuring the curve of the pressure p over time in the sub-chamber by a pressure sensor in the sub-chamber.

6. The method as recited in claim 1, wherein:

the motor vehicle has a start/stop function and

each time the internal combustion engine is restarted, it is inferred from the curve of the pressure p over time in the sub-chamber as to whether the fuel tank vent valve is jammed open.

7. A computer program which is designed to carry out a method for diagnosing a fuel tank vent valve of a motor vehicle, comprising:

inferring, from a curve of a pressure p over time in a sub-chamber of the motor vehicle after a start-up of an internal combustion engine of the motor vehicle, as to whether a fuel tank vent valve is jammed open, the sub-chamber containing the fuel tank of the motor vehicle and being delimited by the fuel tank vent valve.

8. A machine-readable storage medium on which a computer program is stored, the computer program carrying out a method for diagnosing a fuel tank vent valve of a motor vehicle, comprising:

inferring, from a curve of a pressure p over time in a sub-chamber of the motor vehicle after a start-up of an internal combustion engine of the motor vehicle, as to whether a fuel tank vent valve is jammed open, the sub-chamber containing the fuel tank of the motor vehicle and being delimited by the fuel tank vent valve.

9. An electronic control unit for carrying out a diagnosis of a fuel tank vent valve of a motor vehicle with the aid of a method for diagnosing the fuel tank vent valve of the motor vehicle, comprising:

inferring, from a curve of a pressure p over time in a sub-chamber of the motor vehicle after a start-up of an internal combustion engine of the motor vehicle, as to whether a fuel tank vent valve is jammed open, the sub-chamber containing the fuel tank of the motor vehicle and being delimited by the fuel tank vent valve.