Cummins X12 CM2350 X119B (2018 & Newer) Fault Code: 3242 PID: SPN: 3363 FMI: 7 Aftertreatment Diesel Exhaust Fluid Tank Heater- Mechanical System Not Responding or Out of Adjustment

Circuit Description
The aftertreatment diesel exhaust fluid tank heater keeps the diesel exhaust fluid from freezing in the diesel exhaust fluid tank. The tank heater consists of an electrically powered tank heater control valve which controls the flow of engine coolant to a heating coil inside the diesel exhaust fluid tank. The tank heater control valve opens to allow coolant to flow to the heating coil when heating is commanded, and closes when heating is no longer required.

Component Location
The diesel exhaust fluid tank heater control valve is located near the diesel exhaust fluid tank. Specific location will vary depending on the vehicle OEM. The tank heating coil is internal to the diesel exhaust fluid tank.

Conditions for Running the Diagnostics
This diagnostic runs a calibrated amount of time after diesel exhaust fluid tank heating is first commanded.

Conditions for Setting the Fault Codes
The aftertreatment diesel exhaust fluid tank heater was commanded on by the engine engine control module (ECM), but no corresponding temperature increase in the aftertreatment diesel exhaust fluid tank temperature was recorded by the tank temperature sensor.

Action Taken When the Fault Code is Active
The ECM illuminates the amber CHECK ENGINE lamp and/or Malfunction Indicator Lamp (MIL) after the diagnostic fails on two consecutive trips.

Conditions for Clearing the Fault Code
The fault code status in INSITE™ electronic service tool will change to INACTIVE immediately after the system is able to adequately heat and the diagnostic runs and passes. If heating can not be completed, use the “Diesel Exhaust Fluid Doser System Heater Test” found under “ECM Diagnostic Test” in INSITE™ electronic service tool to command heating to the tank heater and all line heaters.
The ECM will turn off the amber CHECK ENGINE lamp immediately after the diagnostic runs and passes.
For On-Board Diagnostics (OBD) engines, the ECM will extinguish the Malfunction Indicator Lamp (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
Possible causes of this fault code include:

Aftertreatment diesel exhaust fluid tank heater control valve stuck closed
Blockage or restrictions in the coolant plumbing to the diesel exhaust fluid tank heater
Engine coolant level low
Malfunctioning aftertreatment diesel exhaust fluid tank heater control valve
Reference the appropriate OEM wiring diagram when troubleshooting circuits that utilize wiring supplied by the OEM.

Possible Cause:
1) Coolant level
2) DEF tank heater control valve failure
3) ECM calibration