Case IH 19748 – DCU (Dosing Control Unit): Too high UREA Temperature in Pump module or Leakage test failed (Emergency shut off)

The system has detected an over-temperature condition regarding the urea (DEF) inside the pump module, or the reagent temperature sensor within the pump module is reading out of its allowable range. This triggers an emergency shut-off of the DEF dosing system, eventually leading to engine derating.

• Tier 4a
• Magnum (180-370, Series 4)
• Steiger (350-600)
• Puma (130-215)
• Maxxum (110-140)
• Optum
• Farmall
• Axial-Flow (5130, 6130, 7130, 7230, 8230, 9230)
• Patriot
• Titan
• Farmlift

1. 1

   Listen to the DEF supply module pump with the engine at idle; continuous cycling indicates a leak or restriction, while no cycling indicates an electrical or motor fault.

2. 2

   Check system pressure using the machine monitor (e.g., Pro 700); normal operating pressure is around 70 psi, and a drop indicates a restriction or leak.

3. 3

   Inspect the main inline filter inside the stainless cartridge of the DEF module and the small inlet screen fitting for contamination from dust or crop debris.

4. 4

   Verify that the inline filter on the DEF tank vent hose is present and intact to prevent debris from entering the tank.

5. 5

   Inspect the wiring harness connecting to the DCU and the DEF pump module for shorts, chafing, or corrosion.

1. 1

   Clean the System

   If pressure is low or the pump is overworking (leading to high temps/leakage faults), remove and inspect the DEF module filters. Clean or replace the main cartridge filter and the inlet fitting filter.

2. 2

   Flush the Tank

   If debris is found in the filters, drain and flush the entire DEF tank to prevent immediate re-contamination.

3. 3

   Install Vent Filter

   If the DEF tank vent hose is missing its filter, install a new one to prevent dust ingress.

4. 4

   Replace the Pump Module

   If the sensor has failed (P2043) or the pump has suffered internal damage causing a persistent leakage code (P202D), replace the entire DEF Supply Module.

5. 5

   Reprogramming

   Install the new DEF dosing module and program/calibrate it to the vehicle's DCU using the OEM diagnostic tool (e.g., EST) after installation to clear the emergency shut-off state.