New Holland DCU 19336 – DCU: System frozen and not free in time | Defreezing Mode and Detection Errors | Pump module - Internal heating - open circuit
Issue description
The Selective Catalytic Reduction (SCR) system utilizes internal heating elements to thaw Diesel Exhaust Fluid (DEF) in cold weather. This code indicates that the Dosing Control Unit (DCU) has detected an "open circuit" (a break in the electrical path) in the DEF pump module's internal heating element. Because the heater is not functioning, the system cannot thaw the frozen DEF in the required time limit, causing the pump to fail to build pressure during its detection mode.
Applies to these machines
15 machines- T6 series (T6.125 - T6.175)
- T7 series (T7.165 - T7.270)
- T8 series (T8.320 - T8.410)
- T9 series (T9.645)
- TS6 series
- CR9090
- CX8080
- CX8090
- Speedrower series
- Magnum (180-340)
- Steiger (350-600)
- Puma
- Maxxum
- Optum
- Patriot Sprayers
Check the cause
Inspect the wiring harness leading to the DEF pump module for chafing, rodent damage, or broken wires
Disconnect the DEF pump module electrical connector and check for corrosion, pushed-out pins, or moisture intrusion
Test the internal heater circuit pins on the DEF pump module for continuity/resistance using a multimeter (an open circuit/infinite resistance reading confirms the internal heating element has failed)
Verify that the supply voltage to the internal heaters (UB1) is present when commanded
Look for other active codes (e.g., 19337 for back-flow line heating open circuit) which might indicate a broader harness failure rather than an isolated pump failure
Repair steps
Preparation
Turn off the machine and disconnect the battery. Ensure the DEF system has completed its purge cycle before disconnecting any lines.
Drain/Disconnect
Place a clean catch pan under the DEF pump module. Disconnect the DEF suction, pressure, and backflow fluid lines from the module. Cap the lines to prevent contamination.
Electrical Disconnect
Unplug the main electrical harness connector from the DEF pump module.
Removal
Remove the mounting bolts securing the DEF pump module to the chassis/bracket and remove the faulty unit.
Installation
Mount the new DEF pump module and torque the bolts to OEM spec. Reconnect the fluid lines (ensure they click/lock into place) and the electrical connector.
Programming/Calibration
The new Bosch DEF pump module will likely need to be programmed and calibrated to the vehicle's DCU using the CNH Electronic Service Tool (EST) / EASY diagnostic software.
Testing
Clear the fault codes. Run the machine and perform a DEF system leak test and heater test via the diagnostic tool to verify pressure build-up and heater operation.
Parts you might need
(15)DEF Pump Module / Urea Supply Module / Bosch Denoxtronic 2.2 AdBlue Pump
84246892Ensure you match the specific Bosch or CNH part number to your exact machine serial number, as flow rates and mounting configurations can vary slightly between the T6/T7 series and the larger articulated T9/Steiger tractors. Programming is required after replacement.
DEF Pump Module / Urea Supply Module / Bosch Denoxtronic 2.2 AdBlue Pump
84246892REnsure you match the specific Bosch or CNH part number to your exact machine serial number, as flow rates and mounting configurations can vary slightly between the T6/T7 series and the larger articulated T9/Steiger tractors. Programming is required after replacement.
DEF Pump Module / Urea Supply Module / Bosch Denoxtronic 2.2 AdBlue Pump
84329595Ensure you match the specific Bosch or CNH part number to your exact machine serial number, as flow rates and mounting configurations can vary slightly between the T6/T7 series and the larger articulated T9/Steiger tractors. Programming is required after replacement.
DEF Pump Module / Urea Supply Module / Bosch Denoxtronic 2.2 AdBlue Pump
5802513621Ensure you match the specific Bosch or CNH part number to your exact machine serial number, as flow rates and mounting configurations can vary slightly between the T6/T7 series and the larger articulated T9/Steiger tractors. Programming is required after replacement.
DEF Pump Module / Urea Supply Module / Bosch Denoxtronic 2.2 AdBlue Pump
5802513621REnsure you match the specific Bosch or CNH part number to your exact machine serial number, as flow rates and mounting configurations can vary slightly between the T6/T7 series and the larger articulated T9/Steiger tractors. Programming is required after replacement.
DEF Pump Module / Urea Supply Module / Bosch Denoxtronic 2.2 AdBlue Pump
5802513624REnsure you match the specific Bosch or CNH part number to your exact machine serial number, as flow rates and mounting configurations can vary slightly between the T6/T7 series and the larger articulated T9/Steiger tractors. Programming is required after replacement.
DEF Pump Module / Urea Supply Module / Bosch Denoxtronic 2.2 AdBlue Pump
47565934Ensure you match the specific Bosch or CNH part number to your exact machine serial number, as flow rates and mounting configurations can vary slightly between the T6/T7 series and the larger articulated T9/Steiger tractors. Programming is required after replacement.
DEF Pump Module / Urea Supply Module / Bosch Denoxtronic 2.2 AdBlue Pump
51515745Ensure you match the specific Bosch or CNH part number to your exact machine serial number, as flow rates and mounting configurations can vary slightly between the T6/T7 series and the larger articulated T9/Steiger tractors. Programming is required after replacement.
DEF Pump Module / Urea Supply Module / Bosch Denoxtronic 2.2 AdBlue Pump
51603476Ensure you match the specific Bosch or CNH part number to your exact machine serial number, as flow rates and mounting configurations can vary slightly between the T6/T7 series and the larger articulated T9/Steiger tractors. Programming is required after replacement.
DEF Pump Module / Urea Supply Module / Bosch Denoxtronic 2.2 AdBlue Pump
84349041Ensure you match the specific Bosch or CNH part number to your exact machine serial number, as flow rates and mounting configurations can vary slightly between the T6/T7 series and the larger articulated T9/Steiger tractors. Programming is required after replacement.
DEF Pump Module / Urea Supply Module / Bosch Denoxtronic 2.2 AdBlue Pump
0444022021Ensure you match the specific Bosch or CNH part number to your exact machine serial number, as flow rates and mounting configurations can vary slightly between the T6/T7 series and the larger articulated T9/Steiger tractors. Programming is required after replacement.
DEF Pump Module / Urea Supply Module / Bosch Denoxtronic 2.2 AdBlue Pump
0444042210Ensure you match the specific Bosch or CNH part number to your exact machine serial number, as flow rates and mounting configurations can vary slightly between the T6/T7 series and the larger articulated T9/Steiger tractors. Programming is required after replacement.
DEF Pump Module / Urea Supply Module / Bosch Denoxtronic 2.2 AdBlue Pump
0444042088Ensure you match the specific Bosch or CNH part number to your exact machine serial number, as flow rates and mounting configurations can vary slightly between the T6/T7 series and the larger articulated T9/Steiger tractors. Programming is required after replacement.
DEF Pump Module / Urea Supply Module / Bosch Denoxtronic 2.2 AdBlue Pump
0444042146Ensure you match the specific Bosch or CNH part number to your exact machine serial number, as flow rates and mounting configurations can vary slightly between the T6/T7 series and the larger articulated T9/Steiger tractors. Programming is required after replacement.
DEF Pump Module / Urea Supply Module / Bosch Denoxtronic 2.2 AdBlue Pump
0444042253Ensure you match the specific Bosch or CNH part number to your exact machine serial number, as flow rates and mounting configurations can vary slightly between the T6/T7 series and the larger articulated T9/Steiger tractors. Programming is required after replacement.
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