New Holland DCU 19757 – DCU: Group error path UREA injection control _Error belonging to group UREA Injection control _ P208B Reagent-pump -Not delivering

This code indicates that the Selective Catalytic Reduction (SCR) system's DEF (Diesel Exhaust Fluid) pump—also known as the reductant or urea pump—is failing to deliver fluid to the dosing injector. The system detects a performance issue where the pump is commanded on but is stuck off, blocked, or otherwise unable to build and deliver pressure.

• T6 Series (T6.125 - T6.180)
• T7 Series (T7.165 - T7.315 HD)
• T8 Series (T8.275 - T8.435)
• T9 Series
• TS6 Series (TS6.110 - TS6.140)
• CR/CX Series Combines
• Speedrower series (160, 220, 260)
• LM series (LM6.35)
• TH series (TH7.42)
• Puma
• Magnum
• Maxxum
• Steiger

1. 1

   Inspect the DEF Tank: Check for frozen fluid, crystallization, or debris in the tank that could starve the pump.

2. 2

   Check the DEF Lines and Fittings: Inspect the supply and return lines. Specifically, check the return line fitting (which contains a return orifice) for blockages.

3. 3

   Inspect Electrical Connections: Check the wiring harness and connectors at the DEF pump for corrosion, unplugged terminals, or damaged wires.

4. 4

   Test Pump Operation: Using the New Holland Electronic Service Tool (EST), run a 'Pressure Build Up Operation' test to manually command the pump and verify if it can generate pressure.

1. 1

   Preparation

   Turn off the machine, disconnect the battery, and ensure the exhaust/SCR system has cooled down.

2. 2

   Drain/Clean

   If contamination is suspected, drain the DEF tank and flush it with distilled water.

3. 3

   Disconnect Lines

   Disconnect the DEF supply and return lines from the DEF pump/dosing module. Cap the lines immediately to prevent dirt ingress and crystallization.

4. 4

   Disconnect Electrical

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

5. 5

   Remove the Pump

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

6. 6

   Install the New Pump

   Mount the new DEF pump module and tighten the bolts to OEM spec.

7. 7

   Reconnect

   Remove the caps and reconnect the DEF fluid lines and the electrical harness.

8. 8

   Refill

   Fill the DEF tank with fresh, high-quality Diesel Exhaust Fluid.

9. 9

   Programming

   Reconnect the battery. The new DEF pump module must be programmed/calibrated to the vehicle's DCU using the OEM diagnostic software.

10. 10

    Verification

    Clear the DCU 19757 / P208B fault codes and run a system pressure test to verify the new pump is delivering fluid correctly.