Method and Device for Examining an Exhaust Gas Sensor
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Abstract
A first voltage (V1) is detected between an auxiliary pump electrode and a reference electrode of an exhaust gas sensor, and a target diagnosis value (SDIAG) is determined as a function of the detected first voltage (V1). A measured current (Im) is detected between a measurement electrode and a second main pump electrode of the exhaust gas sensor, said measured current being set up as the pump current by regulating a second voltage between the measurement electrode and the reference electrode to a pre-defined voltage. An actual diagnosis value (IDIAG) is determined as a function of the detected measured current (Im). An error (ERR) of the exhaust gas sensor is recognized depending on the target diagnosis value (SDIAG) and the actual diagnosis value (IDIAG).
20 Citations
13 Claims
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1-7. -7. (canceled)
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8. A method for testing an exhaust gas sensor having a first chamber, a second chamber, a first diffusion barrier separating the first and second chambers, and a second diffusion barrier forming a gas inlet of the first chamber, the first chamber having first main pump electrode, the second chamber having a measuring electrode and an auxiliary pump electrode, and a second main pump electrode and a reference electrode being disposed outside of the first and second chambers, said method comprising:
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sensing a first voltage between the auxiliary pump electrode and the reference electrode and determining a set point diagnostic value as a function of the sensed first voltage multiplied by a predefined factor and addition of a predefined shift value; sensing a measuring current between the measuring electrode and the second main pump electrode, the measuring current being set as a pump current by adjusting a second voltage between the measuring electrode and the reference electrode to a predefined voltage, and determining an actual diagnostic value as a function of the sensed measuring current; and detecting a fault in the exhaust gas sensor as a function of the set point diagnostic value and the actual diagnostic value. - View Dependent Claims (9, 10, 11, 12)
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13. A device for testing an exhaust gas sensor, the exhaust gas sensor having a first chamber, a second chamber, a first diffusion barrier separating the first and second chambers, and a second diffusion barrier forming a gas inlet of the first chamber, the first chamber having a first main pump electrode and the second chamber has a measuring electrode and an auxiliary pump electrode, and a second main electrode and a reference electrode being disposed outside of the first and second chambers, the device being configured to sense a first voltage between the auxiliary pump electrode and the reference electrode and determine a set point diagnostic value as a function of the sensed first voltage multiplied by a predefined factor and added to a predefined shift value, sense a measuring current between the measuring electrode and the second main pump electrode, the measuring current being set as a pump current by a second voltage between the measuring current being set as a pump current by a second voltage between the measuring electrode and the reference electrode to a predefined voltage, and determine an actual diagnostic value as a function of the sensed measuring current, and detect a fault in the exhaust gas sensor as a function of the set point diagnostic value and the actual diagnostic value.
Specification