New Holland DCU 19047 – DCU: UREA pressure sensor in box (electrical) _signal high _P204D Reagent -pressure sensor -short circuit high

The DEF (Diesel Exhaust Fluid / Urea) pressure sensor is registering a signal voltage that is too high, which the system interprets as a short circuit to battery. The sensor is physically integrated inside the DEF pump module.

• T6 series (T6.125 to T6.175)
• T7 series (T7.165 to T7.270)
• T8 series (T8.320 to T8.355)
• T9 series (T9.645)
• TS6 series
• CR/CX series
• 9090X
• 9080N
• 8030L
• Speedrower series
• LM series telehandlers
• TH series telehandlers
• Magnum
• Puma
• Maxxum
• Optum
• Steiger series

1. 1

   Inspect the wiring harness and connectors leading to the DEF pump module for any signs of chafing, corrosion, or melted wires.

2. 2

   Test the sensor supply and signal circuits at the pump module connector to verify that the signal wire is not externally shorted to a 12V power source (short to battery).

3. 3

   Look for related voltage codes (such as 19038 / P204C for short circuit low, or 19046 / P204A for open circuit). Multiple simultaneous sensor failures point to a shared harness issue or a failed supply voltage circuit.

4. 4

   If the external wiring harness tests good and there is no external short to power, conclude that the internal sensor has failed and the module requires replacement.

1. 1

   Preparation

   Turn off the machine, remove the key, and disconnect the battery to prevent electrical spikes.

2. 2

   Locate the Module

   Locate the DEF pump module (Urea supply module), which is typically mounted near the DEF tank.

3. 3

   Disconnect Electrical

   Unplug the main electrical harness connectors from the DEF pump module.

4. 4

   Disconnect Fluid Lines

   Carefully disconnect the DEF suction, pressure, and backflow lines. Have a clean catch pan ready, as residual DEF fluid will spill. Cap the lines to prevent contamination.

5. 5

   Remove the Pump

   Remove the mounting bolts securing the DEF pump module to its bracket and remove the faulty unit.

6. 6

   Install the New Pump

   Mount the replacement DEF pump module and secure the bolts.

7. 7

   Reconnect Lines and Wiring

   Reconnect the DEF fluid lines (ensuring they are fully seated to prevent leaks) and plug in the electrical connectors.

8. 8

   Programming

   Reconnect the battery. Note: A new DEF pump module will likely need to be programmed/calibrated to the vehicle's ECU using the New Holland Electronic Service Tool (EST) software.

9. 9

   Verification

   Clear the fault codes, start the engine, and run an SCR system test to verify that the system builds pressure and the DCU 19047 / P204D code does not return.