Device and method for monitoring a tank ventilation system
AssigneeBayerische Motoren Werke Aktiengesellschaft
InventorErich Kagleder
Life of this patent
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Abstract
The invention relates to a device and a method for testing a tank ventilation system with a tank ventilation valve in a motor vehicle, comprising an engine speed sensor, an air flow sensor and/or an idle controller for providing an air mass signal, as well as an evaluating unit, which compares the changes in speed and air masses with at least one threshold value when the tank ventilation valve is opened and closed. To improve the diagnosis of the tank ventilation system, it is proposed that the evaluating unit be designed in such a manner that a total reaction value, which is compared with a threshold value, is formed from the engine speeds when the tank ventilation valve is opened and closed as well as the air masses when the tank ventilation valve is closed and opened.
Claims6
Device for testing a tank ventilation system with a tank ventilation valve in a motor vehicle, comprising an engine speed sensor (10), an air flow sensor (12) and/or an idle controller (13) for providing an air mass signal, as well as an evaluating unit (14), which compares the changes in speed and air masses with at least one threshold value when the tank ventilation valve is opened and closed, characterized in that the evaluating unit (14) is designed in such a manner to form a total reaction value from the engine speeds and the air masses when the tank ventilation system is opened and closed and to compare this value with a threshold value.
Method for testing a tank ventilation system with the steps
- measuring the engine speed when the tank ventilation valve is closed (n0),
- measuring the engine speed when the tank ventilation valve is opened (n),
- measuring or determining an air mass when the tank ventilation valve is closed (ml0),
- measuring or determining an air mass when the tank ventilation valve is opened (ml),
- forming a total reaction value from the measured speeds and the measured or determined air masses and
- comparing the total reaction value with the preset threshold value.
Dependencies are inferred from the claim text.