Case IH 19057 – DCU (Dosing Control Unit): UREA Temperature sensor in box (electrical) – signal high

The control module is receiving a voltage signal from the Diesel Exhaust Fluid (DEF/Urea) pump module's internal temperature sensor that exceeds the maximum allowable threshold. This typically points to an open electrical circuit, a short to a high-voltage source, or a completely failed temperature sensor inside the pump module.

• Tier 4a
• Magnum 235
• Magnum 250
• Magnum 280
• Magnum 290
• Magnum 310
• Magnum 340
• Magnum 380
• Steiger 370
• Steiger 420
• Steiger 470
• Steiger 500
• Steiger 540
• Steiger 580
• Puma 150
• Maxxum 115
• Maxxum 125
• Patriot 3340
• Patriot 4440
• Titan

1. 1

   Inspect the wiring harness and connectors running from the DCU to the DEF pump module for chafed wires, corrosion, or disconnected/pushed-out pins

2. 2

   Use a multimeter to check for an open circuit or a short to battery voltage on the temperature sensor signal wire between the DCU and the pump

3. 3

   Measure the resistance of the temperature sensor directly at the DEF pump module pins to verify if the internal sensor is faulty (open circuit)

4. 4

   Verify that there are no missing CAN messages from the main ECU to the DCU

5. 5

   Ensure the DEF tank and line heaters are functioning, as a frozen system failing to thaw can cause abnormal temperature readings

1. 1

   Disconnect power

   Turn off the machine and disconnect the battery or master disconnect switch.

2. 2

   Disconnect harness

   Locate the DEF pump module (usually mounted near the DEF tank) and disconnect its electrical harness.

3. 3

   Clean and inspect connector

   Clean the connector pins with electrical contact cleaner and inspect for water intrusion or corrosion.

4. 4

   Repair wiring

   If the wiring harness is damaged, repair the affected section, reconnect, and re-test the system.

5. 5

   Determine if module replacement is needed

   If the wiring tests good but the sensor resistance is out of range, the DEF pump module must be replaced (the temperature sensor is integrated internally and is generally not serviced separately).

6. 6

   Relieve pressure

   Relieve any residual pressure in the DEF lines.

7. 7

   Disconnect fluid lines

   Disconnect the DEF supply and return fluid lines from the pump module.

8. 8

   Remove faulty module

   Unbolt and remove the faulty DEF pump module.

9. 9

   Install new module

   Install the new DEF pump module, torque the mounting bolts, and reconnect the fluid lines and electrical connector.

10. 10

    Reconnect power

    Reconnect battery power.

11. 11

    Clear fault code

    Connect a diagnostic tool (such as the Case IH EST) to clear fault code 19057 / P2043.

12. 12

    Perform system tests

    Perform a dynamic urea leak test and a dosing system prime/test to ensure the new pump is operating correctly and the temperature reading is registering within the normal range.