Abstract: The present disclosure is related to detection of a failed NOx sensor, which is crucial for modern combustion engine aftertreatment control, but its failure can cause false diagnostics, reduced engine performance, and lengthy troubleshooting. Accordingly, a system and method for detecting a NOx sensor in an engine through a NOx functional test is disclosed with a selective catalytic reduction SCR system, an ammonia source, a regeneration device, a NOx sensor positioned at an output stream of the SCR system, and an electronic control module in communication with the ammonia source and the NOx sensor. Furthermore, the electronic control module is configured to receive one or more signals from the NOx sensor.

Abstract: A system including a nitrogen oxide sensor and a controller is provided. The nitrogen oxide sensor is configured to generate a first signal indicative of nitrogen oxides content in an exhaust gas. The controller is communicably coupled to the nitrogen oxide sensor. The controller configured to receive the first signal indicative of nitrogen oxides content in the exhaust gas. The controller is also configured to receive a second signal corresponding to an operational parameter of a power source. Further, the controller is configured to compare a derivative of the first signal with a derivative of the second signal. The controller is configured to trigger an error counter when an absolute value of the compared derivative crosses a predetermined threshold. Thereafter, the controller is configured to determine a condition of the nitrogen oxide sensor based on a count of the error counter in a predetermined period of time.

Abstract: A system including a nitrogen oxide sensor and a controller is provided. The nitrogen oxide sensor is configured to generate a first signal indicative of nitrogen oxides content in an exhaust gas. The controller is communicably coupled to the nitrogen oxide sensor. The controller configured to receive the first signal indicative of nitrogen oxides content in the exhaust gas. The controller is also configured to receive a second signal corresponding to an operational parameter of a power source. Further, the controller is configured to compare a derivative of the first signal with a derivative of the second signal. The controller is configured to trigger an error counter when an absolute value of the compared derivative crosses a predetermined threshold. Thereafter, the controller is configured to determine a condition of the nitrogen oxide sensor based on a count of the error counter in a predetermined period of time.