Massey Ferguson 3363.05 – Engine ECU: DEF Tank Heater Solenoid Low Amps

The system has detected an open circuit, high resistance, or a failed internal coil within the DEF coolant-flow-control solenoid. This 12V solenoid is responsible for controlling the flow of warm engine coolant through stainless steel tubes inside the DEF tank to thaw the fluid when temperatures drop to or below freezing (12 degrees F / -11 degrees C). Because the amperage is reading lower than expected, the valve cannot be actuated.

• 4710
• 7724S
• 5712SL
• Interim Tier 4 (2012-2015)
• 7722
• 7722S
• 7615
• 5613
• 5713SL
• 7720S
• 7716
• 7718
• T4
• 7715
• 5710SL
• 7726
• 7616
• 7618
• 5608
• 4708
• 7619
• 7626
• 7726S
• 7624
• 4707
• 4709
• 5711SL
• 7614
• 7718S
• 5610
• 7620
• 7719
• 7714
• 7716S
• T4 (2015-2021)
• 5612
• 7622
• 7720
• Tier 4 (2015-2021)
• 5611
• 7715S
• 5609
• 7724

1. 1

   Inspect the wiring harness and connector leading to the DEF tank heater solenoid valve for corrosion, broken wires, or loose connections.

2. 2

   Using a multimeter, test the resistance across the pins of the solenoid valve. An open circuit (infinite resistance) or a reading outside of the manufacturer's specified ohms confirms the solenoid coil has failed internally.

3. 3

   Verify that there is no break in the wiring between the Engine ECU and the solenoid connector.

1. 1

   Preparation

   Park the tractor on a level surface, shut down the engine, set the parking brake, and turn the battery disconnect switch to the OFF position. Note: Wear protective gloves to protect your hands from crystallized DEF.

2. 2

   Drain Coolant

   Drain the engine coolant from the cooling system into a suitable container until the fluid level is below the height of the solenoid valve.

3. 3

   Disconnect Electrical

   Disconnect the electrical harness assembly from the solenoid valve connection.

4. 4

   Remove Hoses

   Loosen the hose clamps on both sides of the valve and pull the coolant hose assemblies off the solenoid.

5. 5

   Remove Valve

   Remove the mounting bolts securing the solenoid valve and remove the faulty unit.

6. 6

   Install New Valve

   Mount the new solenoid valve assembly and tighten the mounting bolts (standard torque is typically around 22 N·m / 195 lb-in).

7. 7

   Reconnect Hoses & Wiring

   Reattach the coolant hoses, tighten the hose clamps (approx. 7 N·m / 62 lb-in), and plug the electrical harness back in.

8. 8

   Refill & Test

   Refill the cooling system with the appropriate extended-life coolant, bleed the system of air, turn the battery switch back on, and clear the fault codes via the diagnostic port.