Circuit DescriptionThe aftertreatment diesel exhaust fluid (DEF) sensor is a smart device that communicates to the ECM via the J1939 datalink. The aftertreatment DEF sensor performs its own internal diagnostics and reports malfunctions back to the primary engine control module via the J1939 datalink. The aftertreatment DEF sensor monitors the tank level, temperature and quality of the DEF fluid. Component LocationThe aftertreatment diesel exhaust fluid (DEF) sensor is located in the aftertreatment DEF tank. Location of the tank and sensor is OEM dependent. Refer to the OEM service manual. Conditions for Running the DiagnosticsThis diagnostic runs continuously when the keyswitch...

Circuit DescriptionThe aftertreatment diesel exhaust fluid quality sensor is a smart device that communicates to the ECM via the J1939 datalink. The aftertreatment diesel exhaust fluid quality sensor performs its own internal diagnostics and reports malfunctions back to the primary engine contol module via the J1939 datalink. The aftertreatment diesel exhaust fluid quality sensor is used to measure the concentration of the aftertreatment diesel exhaust fluid in the tank. Component LocationThe DEF quality sensor is typically mounted in the DEF tank or in-line with the DEF dosing unit supply line. Reference the OEM service manual for a detailed component location...

Circuit DescriptionThe aftertreatment diesel exhaust fluid dosing unit heater is used to defrost and/or prevent freezing of the diesel exhaust fluid dosing unit. Component LocationThe aftertreatment diesel exhaust fluid dosing unit location is original equipment manufacturer (OEM) dependent. Refer to the OEM service manual. Conditions for Running the DiagnosticsThe engine must be turned OFF for period of 8 hours before this diagnostic will run. This diagnostic runs when the keyswitch is turned to the ON position after an 8 hour cold soak. Conditions for Setting the Fault CodesThe Engine Control Module (ECM) detected the aftertreatment diesel exhaust fluid dosing unit...

Circuit DescriptionThe aftertreatment diesel exhaust fluid dosing unit heater is used to defrost and/or prevent freezing of the diesel exhaust fluid dosing unit. Component LocationThe aftertreatment diesel exhaust fluid dosing unit location is original equipment manufacturer (OEM) dependent. Refer to the OEM service manual. Conditions for Running the DiagnosticsThe engine must be turned OFF for period of 8 hours before this diagnostic will run. This diagnostic runs when the keyswitch is turned to the ON position after an 8 hour cold soak. Conditions for Setting the Fault CodesThe Engine Control Module (ECM) detected the aftertreatment diesel exhaust fluid dosing unit...

Circuit DescriptionThe aftertreatment diesel exhaust fluid dosing unit heater is used to defrost and/or prevent freezing of the diesel exhaust fluid dosing unit. Component LocationThe aftertreatment diesel exhaust fluid dosing unit location is original equipment manufacturer (OEM) dependent. Refer to the OEM service manual. Conditions for Running the DiagnosticsThis diagnostic runs when the aftertreatment diesel exhaust fluid dosing unit heater is commanded ON. Conditions for Setting the Fault CodesThe Engine Control Module (ECM) detected the aftertreatment diesel exhaust fluid dosing unit temperature is not changing when the heater is commanded ON. Action Taken When the Fault Code is ActiveThe ECM...