Cummins ISX12 CM2250 (2010-12) Fault Code: 3568 PID: SPN: 5394 FMI: 7 Aftertreatment Diesel Fluid (DEF) Dosing Valve- Mechanical System Not Responding or Out of Adjustment

Circuit Description
The aftertreatment DEF dosing valve is controlled by the aftertreatment DEF controller. When the engine ECM commands DEF dosing, the DEF controller 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 Location
The aftertreatment DEF 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 OEM.

Conditions for Running the Diagnostics
This diagnostic runs when the DEF dosing valve is being commanded on.

Conditions for Setting the Fault Codes
The DEF controller has detected a mechanical malfunction of the DEF dosing valve.

Action Taken When the Fault Code is Active
The ECM illuminates the amber CHECK ENGINE lamp and/or the malfunction indicator lamp (MIL) immediately when the diagnostic runs and fails for two consecutive trips.
DEF injection into the aftertreatment system is disabled.
Engine torque will be reduced if the engine is operated for an extended period of time with this fault active.
Conditions for Clearing the Fault Code
To validate the repair, DEF dosing must be commanded so that the dosing valve is actuated. This can be done by performing the Aftertreatment Diesel Exhaust Fluid Doser Pump Override Test found under “ECM Diagnostic Tests” in INSITE? electronic service tool.
The fault code status displayed by INSITE? electronic service tool will be changed to INACTIVE immediately after the diagnostic runs and passes.
The ECM will turn off the amber CHECK ENGINE lamp after the diagnostic runs and passes.
For On-Board Diagnostic (OBD)engines, the ECM will turn off the MIL after three consecutive trips where the diagnostic runs and passes.
The ?Reset All Faults? command in INSITE? electronic service tool can be used to clear active and inactive faults, as well as extinguish the MIL for OBD applications.

Shop Talk
This fault detects a mechanical malfunction of the DEF dosing valve, or a pin-to-pin short in the DEF dosing valve circuit.

Reference the appropriate OEM wiring diagram when troubleshooting circuits that utilize wiring supplied by the OEM.

For intermittent power supply and data link communication issues with aftertreatment components, it is highly recommended that the OEM Power Distribution Center fuses and relays be thoroughly checked for loose, missing, or intermittent connections.

Contamination of the DEF can be a possible cause for this fault code.

Possible Cause:
1) Aftertreatment DEF controller harness failure
2) Aftertreatment DEF dosing valve failure
3) ECM calibration