New Holland DCU 19748 – DCU: Too high UREA Temperature in Pump module or Leakage test failed (Emergency shut off) _over temperature detection (urea temp. in pump module) _P2043 Reagent -temperature sensor of pump module -Out of range

The internal temperature sensor of the Diesel Exhaust Fluid (DEF/Urea) pump module is detecting a temperature that exceeds safe operating limits, or the sensor's electrical signal is completely out of the plausible range (e.g., due to a short or open circuit). To protect the SCR system from damage, the controller initiates an emergency shut-off of the DEF dosing system.

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1. 1

   Verify Sensor Plausibility: Use a diagnostic tool to view the live DEF pump temperature data. Compare it against the DEF tank temperature and ambient temperature. If the engine is cold but the pump sensor reads extremely hot, the sensor or wiring is faulty.

2. 2

   Check Heating Circuits: If the environmental/tank temperature is normal but the pump is actually overheating, check if the DEF line heaters or pump heating valves are stuck 'on'. Look for a short circuit to the battery on the heating wire or a stuck heating relay.

3. 3

   Inspect Wiring and Connectors: Examine the wiring harness connecting to the DEF pump module for chafing, corrosion, or pin damage that could cause an 'out of range' signal.

4. 4

   Check for Leaks: Inspect the DEF lines, pump fittings, and dosing injector for physical leaks or blockages that could disrupt fluid flow and cooling.

1. 1

   Disconnect battery

   Disconnect the battery to ensure safety while working on the electrical and emissions systems.

2. 2

   Locate DEF pump module

   Locate the DEF pump module (supply module), typically mounted near the DEF tank.

3. 3

   Inspect and clean electrical connector

   Inspect and clean the electrical connector to the pump module. If wiring damage is found, repair the harness.

4. 4

   Test heating circuits

   Test the DEF heating coolant valve and electrical line heaters. If a heater is stuck on, replace the faulty relay or heating valve.

5. 5

   Replace DEF pump module

   If the wiring and heaters are functioning correctly but the sensor still reads out of range, the internal temperature sensor has failed. Because the temperature sensor is integrated into the Bosch Denoxtronic DEF pump module, the entire pump module must be replaced.

6. 6

   Disconnect DEF fluid lines

   Disconnect the DEF fluid lines (suction, pressure, and backflow) from the pump. Be prepared to catch spilled DEF and clean it immediately with warm water, as it is highly corrosive to metal.

7. 7

   Remove old DEF pump module

   Unbolt and remove the old DEF pump module.

8. 8

   Install new DEF pump module

   Install the new DEF pump module and reconnect the fluid lines and electrical harness.

9. 9

   Replace DEF pump filter element

   It is highly recommended to replace the DEF pump filter element at this time.

10. 10

    Reconnect battery and test system

    Reconnect the battery, clear the fault codes using a diagnostic tool, and run a system prime/leakage test to ensure the new pump is operating correctly and the system is sealed.