Method for diagnosing exhaust gas sensors
AssigneeRobert Bosch GmbH
InventorsBernhard Ledermann, Danka Dittmer-Gobeljic, Claudius Bevot, Fabian Baumann
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Abstract
An evaluation and control unit, designed as an ASIC, for operating a broadband lambda sensor that includes at least one electrical line. The evaluation and control unit includes at least one electrical terminal for electrically connecting to the electrical line of the broadband lambda sensor, and a device for determining a setpoint value of a current flowing into the electrical terminal and for comparing this setpoint value with the current actually flowing into the electrical terminal and for comparing with the aid of comparators the electrical potential being applied to the electrical terminal with predefined limits.
Claims8
1-7. (canceled)
An evaluation and control unit, in the form of an ASIC, for operating a broadband lambda sensor that includes at least one electrical line, the evaluation and control unit including at least one electrical terminal for electrically connecting to the electrical line of the broadband lambda sensor, the evaluation and control unit including a device configured to determine a setpoint value of a current flowing into the electrical terminal and to compare the determined setpoint value with a current actually flowing into the electrical terminal, and to compare, using comparators, an electrical potential being applied to the electrical terminal with predefined limits.
A method for diagnosing at least one electrical line of a broadband lambda sensor, the electrical line of the broadband lambda sensor being connected to a terminal of an evaluation and control unit, the evaluation and control unit being in the form of an ASIC and being configured to operate the broadband lambda sensor, the evaluation and control unit including a device configured to determine a setpoint value of a current flowing into the electrical terminal and to compare the determined setpoint value with a current actually flowing into the electrical terminal, and to compare, using comparators, an electrical potential being applied to the electrical terminal with predefined limits, the method comprising:
- ruling out a presence of a short circuit or shunt of the electrical line exactly in the case when neither the electrical potential being applied to the terminal is outside of the predefined limits nor the electric current flowing into the terminal differs from a setpoint value by more than a threshold value;
- and/or
- deducing a short circuit or shunt of the electrical line is deduced exactly in the case when at least one of the following conditions is met:
- the electrical potential being applied to the terminal is outside of the predefined limits,
- the electric current actually flowing into the terminal differs from the setpoint value by more than a threshold value.
Dependencies are inferred from the claim text.