New Holland 19147 – DCU: Reductant Injector Circuit Open Load

The Dosing Control Unit (DCU) has detected an open circuit in the electrical system for the reductant (DEF) dosing valve. An open circuit indicates a break or disconnection in the electrical path, preventing the control module from operating the injector. This failure disables the Selective Catalytic Reduction (SCR) system's ability to inject a precise amount of DEF into the exhaust stream, which is required to reduce NOx emissions.

• T4.75 PowerStar Tier 4B
• T5.100
• T5.110
• T5.120
• Powerstar 65
• Powerstar 75
• Powerstar 90
• Powerstar 100
• Powerstar 110
• Powerstar 120
• T7.170
• T7.185
• T7.200
• T7.210
• B95C
• B110C
• L234
• C234
• C238
• C327
• C332
• C337
• C345
• C362
• SR270
• SV300
• SV340
• TR270B
• TR310B
• TR340
• TR340B
• TV370B
• TV380
• TV450
• TV450B
• TV620B

1. 1

   Visually inspect the wiring harness and connectors between the DCU and the DEF dosing valve for melted or chafed insulation, rodent damage, and corroded or loose pins.

2. 2

   Using a digital multimeter, verify proper voltage (approximately 12V) and a good ground signal at the dosing valve's electrical connector with the key on.

3. 3

   Disconnect the dosing valve and measure resistance across its two terminals. Expected resistance is typically 4.5-9.5 ohms or 11-18 ohms. An infinite reading indicates an open coil.

4. 4

   If injector resistance is within specification, check the continuity of the wiring harness from the DCU connector to the injector connector to locate any breaks.

1. 1

   Confirm the fault

   Use a diagnostic scan tool to clear the fault codes and operate the machine to see if code 19147 (or P2047) returns.

2. 2

   Repair wiring and connectors

   If a wiring issue was identified during continuity checks, repair the damaged section of the harness or replace the faulty connector. Ensure all connections are clean and secure.

3. 3

   Replace dosing valve

   If the injector has an open coil (infinite resistance), replace it. Locate the dosing valve on the exhaust system's decomposition tube. Disconnect the electrical connector and DEF lines (be prepared for some residual DEF fluid). Remove mounting bolts and install the new valve, ensuring any gaskets or seals are correctly fitted. Torque mounting bolts to 9 ft-lbs (120 in-lbs). Reconnect the DEF lines and the electrical connector.

4. 4

   Perform system test

   Use a diagnostic tool to perform a dosing or actuation test. Command the new injector to spray to confirm it produces a fine, even cone-shaped mist.

5. 5

   Final verification

   Clear any remaining fault codes and operate the machine until it reaches operating temperature to ensure the SCR system functions correctly without the code returning.