New Holland 19156 – DCU: Urea Pump Speed - Pump Overspeed

The Dosing Control Unit (DCU) has detected that the urea (DEF) pump is running at a speed that exceeds the predefined maximum limit. This indicates an over-speed condition, which can also be described as the engine control unit (ECU) detecting a high voltage condition in the control circuit for the reductant pump. The system anticipates a certain operational speed for the pump, and when the actual speed feedback is excessively high, it logs this fault as a safety and system protection measure.

• T6.120
• T6.140
• T6.150
• T6.155
• T6.160
• T6.165
• T6.175
• T7.170
• T7.185
• T7.200
• T7.210
• T7.220
• T7.235
• T7.250
• T7.260
• T7.270
• T8 Series
• T9 Series
• Magnum 180
• Magnum 190
• Magnum 210
• Magnum 225
• Magnum 235
• Magnum 260
• Magnum 290
• Magnum 340
• Magnum 370
• Maxxum 110
• Maxxum 115
• Maxxum 120
• Maxxum 125
• Maxxum 130
• Maxxum 140
• Puma 130
• Puma 145
• Puma 160
• Puma 170
• Puma 185
• Puma 200
• Puma 215
• CR6090
• CR7090
• CR8080
• CR8090
• CR8.90
• CR9090
• CR9.90
• CX8070
• CX8090
• LM Series
• Patriot Series
• Titan Series

1. 1

   Use a diagnostic tool to read all fault codes from the DCU and other electronic modules. Note if P208D (19156) is present alone or with other SCR-related codes, as this can guide the diagnostic path.

2. 2

   Carefully inspect the urea pump, its connectors, and the surrounding wiring harness for any signs of physical damage, corrosion, or fluid leaks. Pay close attention to the electrical connector for moisture intrusion.

3. 3

   Disconnect the harness from the urea pump module and check for damaged, bent, or corroded pins in the connector.

4. 4

   Test the wiring harness for continuity and for shorts to power or ground between the DCU and the pump module. A faulty wire can lead to incorrect control signals and pump behavior.

5. 5

   Using a digital multimeter, verify that the pump module is receiving the correct voltage and has a solid ground connection.

6. 6

   Monitor the pump's electrical current draw during operation (if possible with the available diagnostic tool). An abnormally high current draw indicates an internal pump issue, such as a mechanical bind or a failing motor.

1. 1

   Clear fault codes

   Clear all fault codes and operate the machine to see if code 19156/P208D returns immediately. This helps differentiate between intermittent and persistent faults.

2. 2

   Address wiring issues

   If any wiring or connector faults were found during the diagnostic checks, repair or replace the damaged sections of the harness. Ensure all connections are clean, secure, and free of corrosion.

3. 3

   Replace urea pump module

   If the diagnostic checks point towards an internal failure of the urea pump (e.g., confirmed high current draw, persistent fault with good wiring), the pump module should be replaced. The urea pump is typically supplied as a complete module.

4. 4

   Program and calibrate

   After installing a new urea pump/dosing module, it may require programming or calibration to the vehicle's Dosing Control Unit (DCU) using a New Holland electronic service tool (EST) or a compatible high-level aftermarket diagnostic tool. CNH may require evidence of proper troubleshooting before providing necessary passwords for software installation.

5. 5

   System verification

   After repairs are complete and codes are cleared, perform a system verification test. This may involve running the machine for a specific duration to allow the DCU to confirm the SCR system is operating correctly.