Case IH 19155 (F-4374-16) - ECU – DCU (Dosing Control Unit): DEF/AdBlue Supply Module Pump Motor Speed Deviation

The control module monitors the DEF pump motor speed. If the difference between the commanded pump speed and the actual monitored pump speed exceeds a specific threshold (such as 300 rpm), or if the pump motor is physically blocked, this diagnostic trouble code (DTC) is set. When this occurs, the Selective Catalytic Reduction (SCR) system shuts down, which will eventually lead to an engine derate.

• VESTRUM CVX
• Magnum Tractors: 180, 190, 210, 225, 235, 260, 290, 340, 370, 380
• Steiger Tractors: 350, 400, 450, 500, 550, 600 (including Rowtrac and QT models)
• Puma Tractors: 130-215
• Maxxum Tractors: 110-140
• Axial-Flow Combines: 240 series, 5130, 6130, 7130, 7230, 8230, 9230, 7140
• Patriot & Titan Sprayers: 3030, 3530, 4030, 4430, 4540
• Farmlift Telehandlers

1. 1

   Check the DEF supply module wiring harness for defects, including high resistance in the VPWR (power) circuit, high resistance in the GND (ground) circuit, or a short to ground.

2. 2

   Inspect the dosing injector tip and the mixing chamber for scale build-up (white urea deposits) which can cause backpressure and block the pump.

3. 3

   Verify the DEF/AdBlue concentration measures at 32.5% high-grade urea and 67.5% distilled water. Drain and replace if incorrect or contaminated.

4. 4

   Check the DEF supply module filter for blockages that can cause pump deviation.

1. 1

   Turn off ignition

   Turn off the ignition and wait for the normal key-off sequence to finish, allowing the DEF system to complete its purge cycle before disconnecting any power.

2. 2

   Clean components

   If scale build-up was found during diagnostics, clean the dosing injector tip and mixing chamber.

3. 3

   Replace filter

   Replace the DEF supply module filter. Use the specialized extraction tool to remove the old filter element to prevent scratching the inner walls of the pump housing. Ensure the surrounding area is clean of dried white urea crust before opening the filter cap.

4. 4

   Replace DEF Supply Module

   If the wiring is intact, the filter is clean, the fluid is good, and the fault remains active, the reductant pump assembly (DEF Supply Module) is internally damaged and must be replaced.

5. 5

   Install new module

   Install the new DEF Supply Module. If flushing the external housing face, use only clean distilled water to safeguard the internal high-pressure fluid loops.

6. 6

   Clear fault codes

   Use the Electronic Service Tool to clear the fault codes and verify the system is operating properly.