US 2011/0079298 A1 · METHOD AND DEVICE FOR THE FUNCTIONAL TESTING OF A PRESSURE SWITCH OF A TANK VENT SYSTEM FOR AN INTERNAL COMBUSTION ENGINE OF A MOTOR VEHICLE

Abstract

A method for the functional testing of a pressure switch of a tank vent device for an internal combustion engine of a motor vehicle, enables the testing of the pressure switch even while the crankshaft is rotating. The pressure switch is located in a low pressure position if the pressure in the tank vent device is lower than a pressure threshold, and is otherwise in a high pressure position. In a rotating operating state of the crankshaft in which the pressure in an intake pipe exceeds the pressure threshold, a tank vent valve being disposed in a connecting line between a fuel vapor reservoir and the intake pipe is actuated such that the tank vent device and the intake pipe are pneumatically connected to each other. The pressure switch is assessed as defective if it is in the low pressure position after actuation of the tank vent valve.

Claims20

Dependent claims

A method for the functional testing of a pressure switch of a tank vent device for an internal combustion engine of a motor vehicle, with the pressure switch being located in a low-pressure position if the pressure in the tank vent device is lower than a pressure threshold, and said pressure switch otherwise being in a high-pressure position, the method comprising:

in an operating state in which a crankshaft of the internal combustion engine rotates and the pressure in an intake pipe of the internal combustion engine exceeds the pressure threshold, actuating a tank vent valve of the tank vent device, said valve being disposed in a connecting line between a fuel vapor reservoir and the intake pipe, in such a way that the tank vent device and the intake pipe are pneumatically connected,
assessing the pressure switch as defective if the same is in the low-pressure position after actuation of the tank vent valve.

A control device for a motor vehicle, the control device being coupled with a pressure switch of a tank vent device for an internal combustion engine of a motor vehicle, with the pressure switch being located in a low-pressure position if the pressure in the tank vent device is lower than a pressure threshold, and said pressure switch otherwise being in a high-pressure position, wherein the control device is operable

in an operating state in which a crankshaft of the internal combustion engine rotates and the pressure in an intake pipe of the internal combustion engine exceeds the pressure threshold, to actuate a tank vent valve of the tank vent device, said valve being disposed in a connecting line between a fuel vapor reservoir and the intake pipe, in such a way that the tank vent device and the intake pipe are pneumatically connected, and
to assess the pressure switch as defective if the same is in the low-pressure position after actuation of the tank vent valve.

Dependencies are inferred from the claim text.

Method and device for the functional testing of a pressure switch of a tank vent system for an internal combustion engine of a motor vehicle

Life of this patent

Method and device for the functional testing of a pressure switch of a tank vent system for an internal combustion engine of a motor vehicle

Life of this patent

Abstract

Claims20