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Reason:NOx Limits Exceeded Due to Insufficient Reagent Quality – Condition Exists. The diesel exhaust fluid quality is not sufficient enough to provide adequate NOx reduction. Effect:Possible reduced engine performance. Circuit Description:The engine control module (ECM) monitors the NOx concentration in the engine’s exhaust gases using an aftertreatment intake NOx sensor and an aftertreatment outlet NOx sensor. By comparing these two values, the ECM is able to determine the conversion efficiency of the SCR catalyst and dosing system. Component Location:The SCR catalyst is located in the vehicle’s exhaust system, after the diesel particulate filter and decomposition tube. Conditions for Running the...

Reason:Aftertreatment Outlet NOx Sensor Circuit – Abnormal Rate of Change. The aftertreatment outlet NOx sensor reading is not valid. Effect:None on performance. Circuit Description:The 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...

Reason:Aftertreatment Diesel Exhaust Fluid Tank Empty – Condition Exists. The diesel exhaust fluid tank is empty. Effect:Possible reduced engine performance Circuit Description:The aftertreatment diesel exhaust fluid level sensor is used to monitor the diesel exhaust fluid level inside the diesel exhaust fluid tank. Component Location:The aftertreatment diesel exhaust fluid tank level sensor is located in the aftertreatment diesel exhaust fluid tank. Location of the tank and level sensor is OEM dependent. Refer to the OEM service manual. Conditions for Running the Diagnostics:This diagnostic runs continuously when the keyswitch is in the ON position or when the engine is running. Conditions...

Reason:Aftertreatment Diesel Exhaust Fluid Tank Empty – Condition Exists. The diesel exhaust fluid tank is empty. Effect:Possible reduced engine performance Circuit Description:The aftertreatment diesel exhaust fluid level sensor is used to monitor the diesel exhaust fluid level inside the diesel exhaust fluid tank. Component Location:The aftertreatment diesel exhaust fluid tank level sensor is located in the aftertreatment diesel exhaust fluid tank. Location of the tank and level sensor is OEM dependent. Refer to the OEM service manual. Conditions for Running the Diagnostics:This diagnostic runs continuously when the keyswitch is in the ON position or when the engine is running. Conditions...

Reason:Engine Wait to Start Lamp – Abnormal update rate. A loss of communication has been detected. Effect:None on performance Circuit Description:Normally, switches, accelerators, and other components are connected to the engine control module (ECM) directly through individual wires. Multiplexing allows those same components to be hard wired to an original equipment manufacturer (OEM) vehicle electronic control unit (VECU) or transmission electronic control unit (ECU) in the cab. Then component values and states from components such as sensors, accelerators, and switches can be transmitted from the OEM VECU to the Cummins® ECM over the SAE J1939 data link. Component Location:The SAE...