Circuit DescriptionThe aftertreatment diesel exhaust fluid dosing unit performs many functions, one of which is to generate adequate diesel exhaust fluid pressure in the lines, using a pump, to allow for dosing. The ECM provides a battery voltage supply and a ground to the diesel exhaust fluid dosing unit. The ECM also supplies a signal to the dosing unit to control the diesel exhaust fluid output. This signal changes, based on the diesel exhaust fluid pressure being commanded. Component LocationThe aftertreatment diesel exhaust fluid dosing unit location is original equipment manufacturer (OEM) dependent. Refer to the OEM service manual. Conditions...

Circuit DescriptionThe aftertreatment diesel exhaust fluid line heater relay is used to provide power to the aftertreatment diesel exhaust fluid line heaters. Component LocationThe aftertreatment diesel exhaust fluid line heater relay location is original equipment manufacturer (OEM) dependent. Refer to the OEM service manual. Conditions for Running the DiagnosticsThis diagnostic runs when the keyswitch is in the ON position and line heating is commanded ON. Conditions for Setting the Fault CodesThe Engine Control Module (ECM) detected the aftertreatment diesel exhaust fluid line heater relay driver signal was shorted to high source. Action Taken When the Fault Code is ActiveThe ECM...

Circuit DescriptionThe aftertreatment diesel exhaust fluid line heater relay is used to provide power to the aftertreatment diesel exhaust fluid line heaters. Component LocationThe aftertreatment diesel exhaust fluid line heater relay location is original equipment manufacturer (OEM) dependent. Refer to the OEM service manual. 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 the aftertreatment diesel exhaust fluid line heater relay control signal was out or range low or open circuit. Action Taken When the Fault...

Circuit DescriptionThe aftertreatment diesel exhaust fluid dosing valve is controlled by the ECM. When the engine control module (ECM) commands DEF dosing, the ECM sends a pulse width modulated (PWM) signal to the dosing valve, which opens the dosing valve and allows DEF to be sprayed into the exhaust stream. Component LocationThe aftertreatment diesel exhaust fluid dosing valve is installed in the exhaust system. It is mounted directly to the aftertreatment decomposition tube, before the selective catalytic reduction (SCR) catalyst. Installation position will vary, based on the aftertreatment architecture and the original equipment manufacturer (OEM). Conditions for Running the DiagnosticsThis...

Circuit DescriptionThe aftertreatment diesel exhaust fluid (DEF) dosing valve is controlled by the ECM. When the engine control module (ECM) commands DEF dosing, the ECM sends a pulse width modulated (PWM) signal to the dosing valve, which opens the dosing valve and allows DEF to be sprayed into the exhaust stream. Component LocationThe aftertreatment diesel exhaust fluid dosing valve is installed in the exhaust system. It is mounted directly to the aftertreatment decomposition tube, before the selective catalytic reduction (SCR) catalyst. Installation position will vary, based on the aftertreatment architecture and the original equipment manufacturer (OEM). Conditions for Running the...