Case IH 17485 (F-522005-31) - ECU – ECU / DCU: DEF/AdBlue reverting pump driver circuit open failure

The reverting pump reverses the flow of DEF back into the tank when the engine is shut down to prevent freezing and expanding. An open circuit failure means the control module detects no electrical continuity (infinite resistance), indicating a broken wire, an unplugged connector, or a burned-out internal pump motor.

• VESTRUM CVX
• Magnum (180-370)
• Steiger (350-600)
• Puma (130-215)
• Maxxum (110-140)
• Farmall series
• Axial-Flow 130, 230, and 240 series (5130, 7230, 8230, 9230)
• Patriot (4430)
• Titan series
• Farmlift Telehandlers
• Case Wheel Loaders (G-Series)

1. 1

   Inspect the wiring harness running from the Engine ECU/DCU to the DEF Supply Module for chafed wires, rodent damage, or tight bends.

2. 2

   Disconnect the main electrical plug at the DEF Supply Module and check for pushed-out pins, corrosion, or DEF fluid intrusion.

3. 3

   Perform a circuit continuity test across the reverting pump/valve pins on the supply module side (an infinite ohms/OL reading indicates internal motor/valve failure).

4. 4

   Pin out the wiring harness from the ECU connector to the DEF Supply Module connector to ensure supply and ground wires are intact.

1. 1

   Preparation

   Turn off the machine, remove the key, and disconnect the battery to prevent electrical spikes.

2. 2

   Clean the Area

   Thoroughly clean the area around the DEF Supply Module to prevent dirt from entering the DEF lines.

3. 3

   Disconnect Lines

   Disconnect the DEF suction, pressure, and return lines. Note: If the reverting pump failed, there may still be fluid in the lines. Have a clean catch pan ready. Disconnect the engine coolant lines routed to the module (if equipped with a heater valve).

4. 4

   Remove the Module

   Unplug the electrical connector and unbolt the DEF Supply Module from its mounting bracket.

5. 5

   Install New Module

   Mount the replacement DEF Supply Module. Reconnect the coolant lines, DEF lines, and the electrical harness.

6. 6

   Filter Replacement

   Replace the DEF Supply Module filter (main inline filter) during this service.

7. 7

   System Prime and Test

   Reconnect the batteries. Using the Case IH Electronic Service Tool (EST), clear the fault codes. Run the 'Urea Dosing System Test' (UDST) or 'Reverting Valve Check' via the software. This will command the pump to run, bleed air from the system, and verify that the open circuit fault does not return.