New Holland DCU 18147 – DCU (Dosing Control Unit): Dosing Valve (electrical) | open load | P2047 Reductant Injector - circuit open

The control module has detected an 'open load' (an open electrical circuit) in the Diesel Exhaust Fluid (DEF) Dosing Valve, also known as the Reductant Injector. The system is unable to detect the electrical resistance of the injector's internal coil, indicating that the circuit is physically broken, unplugged, or the internal coil of the injector has burned out.

• New Holland T6 Series Tractors
• New Holland T7 Series Tractors
• New Holland T8 Series Tractors
• New Holland T8.360

1. 1

   Visual Inspection: Locate the DEF Dosing Valve (mounted directly on the exhaust pipe/SCR catalyst) and check the electrical connector to ensure it is securely plugged in and the locking tab is intact.

2. 2

   Wiring Harness Check: Inspect the wiring harness running from the DCU to the DEF injector for melted insulation, chafing, or severed wires, especially near the hot exhaust.

3. 3

   Connector Pin Check: Disconnect the injector plug and inspect both sides of the terminal for bent pins, heavy corrosion, or DEF fluid intrusion.

4. 4

   Resistance Test (Multimeter): Measure the electrical resistance across the pins of the DEF Dosing Valve. A healthy coil reads around 12.8 ohms. If it reads OL (Open Loop), the internal coil has failed.

1. 1

   Safety Prep

   Turn off the machine, remove the key, and disconnect the battery to prevent electrical spikes. Ensure the exhaust system has completely cooled.

2. 2

   Relieve Pressure

   If the machine was recently run, wait for the DEF system to complete its purge cycle.

3. 3

   Disconnect Lines

   Unplug the electrical harness from the dosing valve. Disconnect the DEF fluid supply line from the injector (be prepared with a rag to catch minor DEF spillage).

4. 4

   Remove the Valve

   Remove the V-band clamp or mounting bolts securing the dosing valve to the exhaust pipe. Pull the old valve out.

5. 5

   Clean the Port

   Thoroughly clean the mounting flange and port on the exhaust pipe to ensure the new injector seats properly and seals exhaust gases.

6. 6

   Install New Valve

   Install the new DEF Dosing Valve using a new OEM gasket/seal. Tighten the clamp/bolts to OEM torque specs.

7. 7

   Reconnect

   Reattach the DEF supply line and plug in the electrical connector. Reconnect the battery.

8. 8

   Clear Codes & Test

   Connect a diagnostic tool (such as CNH Electronic Service Tool or Jaltest) to clear the DCU 18147 / P2047 fault codes. Run a forced 'AdBlue/DEF dosing valve control test' or leak test via the software to prime the system and verify the new injector is spraying correctly without leaks.