Nitrogen oxide sensor stuck-in-range diagnostic tool

A vehicle includes an engine, an exhaust system, an SCR device, upstream and downstream NOx sensors, and a controller. The controller is in electrical communication with the NOx sensors, and is configured for detecting a stuck-in-range fault condition of the downstream NOx sensor during a low exhaus...

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Bibliographische Detailangaben
Hauptverfasser: SHETNEY JUSTIN A, FELDMANN SCOTT T
Format: Patent
Sprache:chi ; eng
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Beschreibung
Zusammenfassung:A vehicle includes an engine, an exhaust system, an SCR device, upstream and downstream NOx sensors, and a controller. The controller is in electrical communication with the NOx sensors, and is configured for detecting a stuck-in-range fault condition of the downstream NOx sensor during a low exhaust flow condition. The controller detects the condition, receives the upstream and downstream NOx levels from the respective upstream and downstream NOx sensors, and compares these levels to a zero or near-zero threshold when the low exhaust flow condition is active. The controller is also configured for executing a first control action when the upstream NOx level is below the threshold and the downstream NOx level exceeds the threshold, and executing a second control action when neither of the levels exceeds the threshold. A method is also disclosed for diagnosing the stuck-in-range condition.