Cummins ISX12 CM2250 (2010-12) Fault Code: 3574 PID: SPN: 4334 FMI: 18 Aftertreatment Diesel Exhaust Fluid Pressure Sensor- Data Valid But Below Normal Operating Range- Moderately Severe Level

Circuit Description
The diesel exhaust fluid controller provides a 5 volt supply and a ground to the diesel exhaust fluid pressure sensor. The pressure sensor provides a signal to the diesel exhaust fluid controller on the sensor signal circuit. The sensor signal voltage changes, based on the diesel exhaust fluid pressure supplied by the dosing unit. The diesel exhaust fluid controller will detect a low signal voltage at low diesel exhaust fluid pressures, and a high signal voltage at high diesel exhaust fluid pressures. The aftertreatment diesel exhaust fluid pressure sensor reading is communicated to the engine control module (ECM) via the engine data link.

Component Location
The aftertreatment diesel exhaust fluid pressure sensor is internal to the aftertreatment diesel exhaust fluid dosing unit and can not be serviced separately.

Conditions for Running the Diagnostics
This diagnostic runs when the diesel exhaust fluid dosing unit is in the priming or dosing state.

Conditions for Setting the Fault Codes
The diesel exhaust fluid controller detects that the dosing unit is unable to build or maintain adequate diesel exhaust fluid line pressure.

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.
Engine torque will be reduced if the engine is operated for a limited period of time with the fault code active.
Engine torque will be severely reduced and vehicle speed will be limited to 8 km [5 mi] per hour after extended engine operation with the fault code active.
Conditions for Clearing the Fault Code
To validate the repair, perform 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 change 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 Diagnostics (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
Troubleshoot other active selective catalyst reduction (SCR) related faults before this fault.

Possible causes of this fault code include:

Low diesel exhaust fluid tank level
Blocked, restricted, or frozen diesel exhaust fluid dosing unit supply line
Blocked or restricted diesel exhaust fluid tank filter
Blocked or restricted diesel exhaust fluid dosing unit filter
Blocked or restricted diesel exhaust fluid dosing unit supply line fitting
Malfunctioning diesel exhaust fluid dosing unit
Contaminated diesel exhaust fluid
Debris from the diesel exhaust fluid tank. If debris is found in the diesel exhaust fluid tank, clean the diesel exhaust fluid tank thoroughly and fill with certified diesel exhaust fluid.
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.

Possible Cause:
1) N/A