Case IH 17778 (F-5862-17) - ECU – Engine Control Unit (ECU) / DCU (Dosing Control Unit): DEF/AdBlue supply module pump motor Temperature below minimal limit

The system's monitoring software has detected that the temperature reading for the DEF (Diesel Exhaust Fluid) pump motor has dropped below the minimum allowable threshold. This condition typically points to a failure of the temperature sensor internal to the DEF pump motor, a malfunction in the module's heating circuit, or an electrical/wiring failure preventing the sensor from reporting the correct value.

• VESTRUM CVX
• Axial-Flow series (5130, 6130, 7130, 7230, 8230, 9230, 240/250 series)
• Magnum (180 through 370)
• Steiger (350 through 600)
• Maxxum (110 through 140)
• Puma (130 through 215)
• Farmall series
• Patriot series (2250, 3240, 3340, 4430)
• Titan series
• Farmlift series (632, 635, 735, 742, 935)

1. 1

   Inspect the DEF supply module wiring harness for defects, shorts, or open circuits between the module and the ECU/DCU

2. 2

   Check the operation of the system by temporarily connecting a known-good DEF supply module. If the fault clears, the original module is defective

3. 3

   Verify that the ECU/DCU itself is not defective and is sending/receiving the proper voltage signals

1. 1

   Turn off the machine and disconnect the battery.

2. 2

   Locate the DEF supply module (pump unit).

   Typically mounted near the DEF tank.

3. 3

   Carefully disconnect the electrical harness and the DEF fluid lines from the module.

   Note: DEF fluid is corrosive; clean up any spills immediately.

4. 4

   Unbolt and remove the defective DEF supply module.

5. 5

   Install the replacement DEF supply module.

   Reconnect the fluid lines and electrical harness.

6. 6

   Reconnect the battery.

7. 7

   Use a dealer-level diagnostic tool (such as the Jaltest agricultural kit or Case IH EST) to clear the fault codes.

   The new Bosch DEF module will likely need to be programmed/calibrated to the vehicle's ECU after replacement.