Granted Patent B2

US 12,455,205 · App. 18/359,049 · Granted Oct 28, 2025

Inventor: Thomas Pichler (Hohenau, DE)

Assignee: Vitesco Technologies GmbH

G01L27/007F02M25/0809F02M25/0854F02M25/0872

Abstract

Claims (60)

1 . A method for pressure sensor diagnosis in a tank venting system of a motor vehicle operated by an internal combustion engine, the tank venting system includes an activated carbon filter, a purge line arranged between the activated carbon filter and an intake tract of the motor vehicle, a tank venting valve arranged in the purge line and a pressure sensor arranged in the purge line, the method comprises:

measuring a pressure prevailing in the purge line by the pressure sensor to determine a starting pressure;

classifying the starting pressure into one of a plurality of pressure ranges depending on an amplitude of the starting pressure, the plurality of pressure ranges includes a positive pressure range, an ambient pressure range and a negative pressure range; and

carrying out a pressure sensor diagnosis using a diagnosis algorithm which is associated with the pressure range in which the starting pressure lies,

wherein the diagnosis algorithm associated with the positive pressure range comprises:

determining whether a pressure sensor offset fault or a sticking pressure sensor fault has occurred;

suspecting that a pressure sensor offset fault has occurred;

observing a minimum actuation of the tank venting valve with an actuation value which is greater than a predetermined first threshold value;

checking whether a pressure gradient generated across the tank venting valve as a result of the minimum actuation is greater than a predetermined second threshold value;

detecting that a pressure sensor offset fault has occurred if the check reveals that the pressure gradient generated across the tank venting valve as a result of the minimum actuation is greater than the predetermined second threshold value; and

detecting that a sticking pressure sensor fault has occurred if the check reveals that the pressure gradient generated across the tank venting valve as a result of the minimum actuation is not greater than the predetermined second threshold value.

2 . The method of claim 1 , wherein the diagnosis algorithm associated with the negative pressure range determines whether the pressure sensor is operating faultlessly or has a pressure sensor offset fault or a sticking pressure sensor fault.

3 . The method of claim 2 , further comprising determining whether a region of the purge line which lies upstream of the pressure sensor is blocked.

4 . The method of claim 2 , wherein the diagnosis algorithm associated with the negative pressure range includes:

suspecting that a pressure sensor offset fault has occurred;

checking whether the pressure downstream of the tank venting valve is different from the starting pressure;

integrating the tank venting volume flow during an uninterrupted active tank venting valve actuation until the volume present in the purge line up to the activated carbon filter is reached;

checking whether the difference between the purge line pressure and the pressure downstream of the tank venting valve is less than a predetermined third threshold value;

if this is the case, detecting that a functional pressure sensor is present;

if this is not the case, checking whether the maximum value of the difference between the purge line pressure and the starting pressure is greater than a predetermined fourth threshold value;

if this is not the case, detecting that a sticking pressure sensor fault has occurred;

if this is the case, waiting until the tank venting valve is closed for a minimum adjustment time;

checking whether the difference between the purge line pressure and the starting pressure is less than a predetermined fifth threshold value;

if this the case, detecting that a pressure sensor offset fault has occurred; and

if this is not the case, detecting that a pressure sensor offset fault has not occurred.

5 . The method of claim 2 , wherein the diagnosis algorithm associated with the ambient pressure range determines whether a sticking pressure sensor fault has occurred.

6 . The method of claim 5 , further comprising: when determining whether a sticking pressure sensor fault has occurred, performing an analysis of one or more events which cause a pressure change in the purge line in the nominal system.

7 . The method of claim 5 , further comprising: when determining whether a sticking pressure sensor fault has occurred, checking whether a difference between the purge line pressure and the starting pressure is greater than a predetermined sixth threshold value.

8 . The method of claim 7 , further comprising: when the difference between the purge line pressure and the starting pressure is greater than a predetermined sixth threshold value, detecting that a sticking pressure sensor fault has not occurred.

9 . The method of claim 7 , further comprising: when the difference between the purge line pressure and the starting pressure is not greater than a predetermined sixth threshold value, detecting that a sticking pressure sensor fault has occurred.

10 . A device for pressure sensor diagnosis in a tank ventilation system of a motor vehicle operated by an internal combustion engine, the device comprising:

a control unit (ECU) designed to control the method of claim 1 .

11 . A method for pressure sensor diagnosis in a tank venting system of a motor vehicle operated by an internal combustion engine, the tank venting system includes an activated carbon filter, a purge line arranged between the activated carbon filter and an intake tract of the motor vehicle, a tank venting valve arranged in the purge line and a pressure sensor arranged in the purge line, the method comprises:

measuring a pressure prevailing in the purge line by the pressure sensor to determine a starting pressure;

classifying the starting pressure into one of a plurality of pressure ranges depending on an amplitude of the starting pressure, the plurality of pressure ranges includes a positive pressure range, an ambient pressure range and a negative pressure range; and

carrying out a pressure sensor diagnosis using a diagnosis algorithm which is associated with the pressure range in which the starting pressure lies,

wherein the diagnosis algorithm associated with the negative pressure range includes:

determining whether the pressure sensor is operating faultlessly or has a pressure sensor offset fault or a sticking pressure sensor fault;

suspecting that a pressure sensor offset fault has occurred;

checking whether the pressure downstream of the tank venting valve is different from the starting pressure;

integrating the tank venting volume flow during an uninterrupted active tank venting valve actuation until the volume present in the purge line up to the activated carbon filter is reached;

checking whether the difference between the purge line pressure and the pressure downstream of the tank venting valve is less than a predetermined third threshold value;

if this is the case, detecting that a functional pressure sensor is present;

if this is not the case, checking whether the maximum value of the difference between the purge line pressure and the starting pressure is greater than a predetermined fourth threshold value;

if this is not the case, detecting that a sticking pressure sensor fault has occurred;

if this is the case, waiting until the tank venting valve is closed for a minimum adjustment time;

checking whether the difference between the purge line pressure and the starting pressure is less than a predetermined fifth threshold value;

if this the case, detecting that a pressure sensor offset fault has occurred; and

if this is not the case, detecting that a pressure sensor offset fault has not occurred.

12 . A device for pressure sensor diagnosis in a tank ventilation system of a motor vehicle operated by an internal combustion engine, the device comprising:

a control unit (ECU) designed to control the method of claim 11 .

13 . A method for pressure sensor diagnosis in a tank venting system of a motor vehicle operated by an internal combustion engine, the tank venting system includes an activated carbon filter, a purge line arranged between the activated carbon filter and an intake tract of the motor vehicle, a tank venting valve arranged in the purge line and a pressure sensor arranged in the purge line, the method comprises:

measuring a pressure prevailing in the purge line by the pressure sensor to determine a starting pressure;

classifying the starting pressure into one of a plurality of pressure ranges depending on an amplitude of the starting pressure, the plurality of pressure ranges includes a positive pressure range, an ambient pressure range and a negative pressure range; and

carrying out a pressure sensor diagnosis using a diagnosis algorithm which is associated with the pressure range in which the starting pressure lies,

wherein the diagnosis algorithm associated with the ambient pressure range includes:

determining whether a sticking pressure sensor fault has occurred by checking whether a difference between the purge line pressure and the starting pressure is greater than a predetermined sixth threshold value; and

when the difference between the purge line pressure and the starting pressure is greater than a predetermined sixth threshold value, detecting that a sticking pressure sensor fault has not occurred.

14 . A device for pressure sensor diagnosis in a tank ventilation system of a motor vehicle operated by an internal combustion engine, the device comprising:

a control unit (ECU) designed to control the method of claim 13 .

Assignments (1)

Priority Claims (1)

Continuity (2)

References Cited (20)