Circuit DescriptionThe aftertreatment outlet NOx (nitrogen oxides) sensor is a smart device and communicates with the engine control module (ECM) via the J1939 data link. The aftertreatment outlet NOx sensor performs its own internal diagnostics and reports malfunctions back to the primary ECM using the J1939 data link. The NOx sensor is permanently attached to the NOx control module. They are serviced as a single component and can not be replaced individually. The aftertreatment outlet NOx sensor is used to measure the NOx emissions at the outlet of the aftertreatment system. Component LocationThe aftertreatment outlet NOx sensor location can vary...

Circuit DescriptionThe aftertreatment intake NOx (nitrogen oxides) sensor is a smart device and communicates with the engine control module (ECM) via the J1939 data link. The aftertreatment intake NOx sensor performs internal diagnostics and reports malfunctions back to the primary ECM using the J1939 data link. The NOx sensor is permanently attached to the NOx control module. They are serviced as a single component and can not be replaced individually. The aftertreatment intake NOx sensor is used to measure the NOx emissions at the intake of the aftertreatment system. Component LocationThe aftertreatment intake NOx sensor is mounted on the engine...

Circuit DescriptionThe ECM has internal diagnostics that continuously run and check the internal memory. Component LocationThe ECM mounting location varies, depending on the engine model, and may be mounted either on or off the engine. Conditions for Running the DiagnosticsThis diagnostic runs continuously when the keyswitch is in the ON position or when the engine is running. Conditions for Setting the Fault CodesThe Engine Control Module (ECM) detected a software or calibration error. Action Taken When the Fault Code is ActiveThe ECM illuminates the red STOP ENGINE lamp and/or the Malfunction Indicator Lamp (MIL) immediately when the diagnostic runs and...

Circuit DescriptionThe ECM continuously monitors the engine’s fault code status to determine if any fault codes critical to successful engine operation are active. Component LocationThe ECM mounting location varies, depending on the engine model, and may be mounted either on or off the engine. Conditions for Running the DiagnosticsThis diagnostic runs continuously when the engine is running. Conditions for Setting the Fault CodesThe Engine Control Module (ECM) detected the engine has been operated for an extended amount of time with critical SCR faults active, and no repair action has been taken. This amount of time will vary, depending on which...

Circuit DescriptionThe ECM continuously monitors the engine’s fault code status to determine if any fault codes critical to successful engine operation are active. Component LocationThe ECM mounting location varies, depending on the engine model, and may be mounted either on or off the engine. Conditions for Running the DiagnosticsThis diagnostic runs continuously when the engine is running. Conditions for Setting the Fault CodesThe Engine Control Module (ECM) detected that certain critical fault codes related to engine operation were active and the engine continued to operate. Action Taken When the Fault Code is ActiveThe ECM illuminates the amber CHECK ENGINE lamp...