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US 12,169,155 B2Granted
System and method for diagnosing an exhaust gas sensor
AssigneeFord Global Technologies, LLC
InventorsAndrew Bagnasco, Jose Francisco Martinez Leyva, Tyler DeWine, Hassene Jammoussi, Adam Krach, Gladys Galicia
Life of this patent
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Abstract
A method and system for monitoring an exhaust gas sensor coupled in an engine exhaust is provided. In one example, the method determines an estimate of an exhaust gas oxygen sensor time constant according to a comparison of air/fuel ratios and a system time constant.
Claims19
A method of monitoring an exhaust gas sensor in an engine exhaust passage, comprising:
- generating an indication of exhaust gas sensor degradation via a controller according to a time constant of the exhaust gas sensor exceeding a threshold during a fuel cut-off entry and exit, the time constant of the exhaust gas sensor estimated based on a comparison of air/fuel ratios of the exhaust gas sensor;
- and
- adjusting engine fuel delivery based on the time constant.
A system for a vehicle, comprising:
- an engine including a fuel injection system;
- an exhaust gas sensor coupled in an exhaust system of the engine;
- and
- a controller including instructions executable to:
- estimate an oxygen sensor time constant via monitoring a current air/fuel ratio and a previous air/fuel ratio during a fuel cut-off entry and exit;
- comparing the current and previous air/fuel ratios to a starting air/fuel ratio and an expected final air/fuel ratio;
- indicate a presence or an absence of degradation of the exhaust gas sensor in response to the oxygen sensor time constant;
- and
- adjust engine fuel delivery based on the oxygen sensor time constant.
6 more elements
A method of monitoring an exhaust gas sensor in an engine exhaust passage, comprising:
- generating an indication of exhaust gas sensor degradation via a controller according to a time constant of the exhaust gas sensor exceeding a threshold, the time constant of the exhaust gas sensor estimated based on based on a comparison of air/fuel ratios of the exhaust gas sensor during a fuel cut-off entry and a fuel cut-off exit;
- and
- adjusting parameters of a fuel controller according to the time constant of the exhaust gas sensor to adjust engine fuel delivery based on the time constant.
Dependencies are inferred from the claim text.