Massey Ferguson E521010.06 – Engine Control Unit (ECU): The DEF Tank Heater Solenoid Valve High Amps

This fault code indicates that the control module has detected an abnormally high electrical current (amperage) on the circuit that controls the DEF (Diesel Exhaust Fluid) tank heater solenoid valve.

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

1. 1

   Inspect the wiring harness running from the ECU to the DEF tank heater solenoid valve for chafed wires, melted insulation, or areas where the harness may be rubbing against the frame, causing a short to ground.

2. 2

   Disconnect the harness at the solenoid valve and check for water intrusion, corrosion, or damaged pins.

3. 3

   Using a multimeter, measure the resistance (Ohms) across the pins of the DEF heater solenoid valve itself. If the resistance is near zero (continuity) or significantly below OEM specifications, the internal coil is shorted.

4. 4

   With the valve disconnected, turn the key ON and check the supply voltage wire from the ECU. Test the ground circuit for proper continuity.

1. 1

   Preparation

   Park the tractor on a level surface, turn off the engine, and turn the battery disconnect switch to the OFF position.

2. 2

   Drain Coolant

   Locate the DEF tank heater solenoid valve (usually situated on the coolant lines routing toward the DEF tank). Drain the engine coolant into a clean container to a level below the solenoid valve to prevent spillage.

3. 3

   Disconnect Electrical

   Unplug the electrical harness connector from the solenoid valve.

4. 4

   Remove Hoses

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

5. 5

   Remove Valve

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

6. 6

   Install New Valve

   Mount the new solenoid valve and tighten the retaining bolts to OEM torque specs (typically snug, around 22 N·m / 195 lb-in depending on the exact bracket).

7. 7

   Reconnect Hoses & Wiring

   Reattach the coolant hoses, tighten the hose clamps securely, and plug in the electrical connector.

8. 8

   Refill and Bleed

   Refill the engine cooling system. Start the engine, turn the cab heater on high to help bleed air from the cooling circuit, and check the new valve for coolant leaks.

9. 9

   Clear Codes

   Use a diagnostic scan tool to clear the E521010.06 fault code from the ECU.