Cummins ISB4.5 CM2150 Fault Code: 3569 PID: SPN: 3362 FMI: 7 Aftertreatment Diesel Exhaust Fluid Dosing Unit Lines – Mechanical System Not Responding or Out of Adjustment.

Circuit Description
The DEF dosing unit supplies DEF to the aftertreatment nozzle through the nozzle supply line.

Component Location
There are three DEF lines. One line is between the dosing unit and aftertreatment nozzle, and the other two lines are between the dosing unit and DEF tank. These lines can be partially hidden from view by the selective catalytic reduction (SCR) system and other vehicle components. Line routing will vary, based on aftertreatment architecture and the original equipment manufacturer (OEM).

Conditions for Running the Diagnostics
This diagnostic runs continuously while the SCR system is dosing DEF into the aftertreatment system.

Conditions for Setting the Fault Codes
The DEF dosing unit has detected a blockage in the nozzle supply line (between the dosing unit and the aftertreatment nozzle).

Action Taken When the Fault Code is Active
-The ECM illuminates the amber CHECK ENGINE lamp and/or the MIL immediately after the diagnostic runs and fails.
-Engine torque will be reduced.

Conditions for Clearing the Fault Code
-The “active” fault code can not be cleared with INSITE™ electronic service tool.
-To validate the repair, it is necessary to use the INSITE™ electronic service tool to perform the Diesel Exhaust Fluid Doser Pump Override Test.
-Make sure that the diesel exhaust fluid dosing unit is able to successfully cycle through all phases (priming, dosing, and purging) and that diesel exhaust fluid flows evenly from the aftertreatment nozzle.
-The ECM will turn off the amber CHECK ENGINE lamp and/or Malfunction Indicator Lamp (MIL) immediately after the diagnostic runs and passes.
-Use INSITE™ electronic service tool to verify that the fault code is inactive.
-The inactive fault code will be cleared from the memory after 9600 hours of engine operation without a reoccurrence.

Shop Talk
This fault indicates that the diesel exhaust fluid dosing unit was able to build pressure, but not able to spray diesel exhaust fluid into the exhaust stream.

Possible Causes
-Blocked or restricted aftertreatment nozzle
-Blocked or restricted aftertreatment nozzle supply line
-Malfunctioning diesel exhaust fluid dosing unit.

Some crystal build up occurs naturally during normal operation, but can be accelerated by incomplete purging. If blocked diesel exhaust fluid lines due to buildups are detected, make sure that the dosing unit is purging correctly at key OFF. Incomplete purge counts can be viewed using the Data Monitor/Logger menu in the aftertreatment section of INSITE™ electronic service tool. Incomplete purge counts are not necessarily detrimental to operation, but can be used as an indicator to assist in troubleshooting purge effectiveness. If the vehicle is equipped with a battery isolation switch, it should have a built-in delay device to prevent powering down of the dosing unit until the purge sequence is complete.