Case IH 19505 – DCU (Dosing Control Unit) / DeNOx module: Urea box temperature sensor plausibility error (dynamic / static) - Reagent - temperature sensor of pump module - out of range.

The system has detected that the temperature sensor located inside the DEF (Diesel Exhaust Fluid / Urea) pump module is reporting an implausible temperature value (either statically stuck or dynamically out of the expected operating range).

• Tier 4a
• Tier 4b
• Magnum Tractors: 235 - 340 (Series 4)
• Steiger Tractors: 350, 400, 450, 500, 550, 600 (NA and Rowtrac models)
• Puma Tractors
• Axial-Flow Combines: 7230, 8230, 9230

1. 1

   Connect an electronic service tool and check the pump module temperature reading via diagnostics (Service $21 02 07)

2. 2

   Use an external tool (such as an infrared thermometer) to measure the actual physical temperature of the DEF pump module

3. 3

   Compare the diagnostic reading to your external thermometer. If the difference is lower than 10°C, the sensor itself is functioning correctly

4. 4

   If the sensor tests OK, check the DEF tank temperature sensor, as well as the wiring harness and connectors between the DCU and the pump module for shorts, high resistance, or corrosion

1. 1

   Turn off the machine and disconnect the battery

   Ensure the DEF system is depressurized and powered down.

2. 2

   Locate the DEF pump module

   Locate the DEF pump module (supply module) on the machine.

3. 3

   Inspect the wiring harness and main electrical connector

   Inspect the wiring harness and the main electrical connector at the pump module. Look for pushed pins, water intrusion, or wire chafing. Repair any harness damage found.

4. 4

   Determine if internal temperature sensor has failed

   If the wiring is intact and the diagnostic temperature delta (from the checks above) exceeds 10°C, the internal temperature sensor has failed.

5. 5

   Prepare to replace the DEF pump module

   Because the temperature sensor is integrated internally into the DEF pump module, the entire DEF pump module (supply module) must typically be replaced.

6. 6

   Remove DEF lines and electrical connectors

   Remove the DEF lines and electrical connectors from the pump module.

7. 7

   Remove the faulty DEF pump module

   Unbolt and remove the faulty DEF pump module.

8. 8

   Install the replacement module

   Install the replacement module, reconnect the DEF lines, and plug in the electrical harness.

9. 9

   Reconnect battery and clear fault codes

   Reconnect the battery, clear the fault codes using the electronic service tool, and run the system to ensure the DCU registers a plausible temperature and the code does not return.