Massey Ferguson E3363.31 – Engine Control Unit (ECU): The DEF Tank Heater Solenoid Valve High Voltage (ECU)

The controller has detected an electrical issue—specifically an abnormally high voltage, short circuit to a high source, or an over-temperature condition on the power stage of the circuit controlling the DEF tank heater coolant valve.

• 7616
• 5612
• 7622
• Interim Tier 4 (2012-2015)
• 7614
• 5611
• 7615
• 5610
• 5613
• 7620
• 5609
• 7618
• 5608
• 7619
• 7626
• 7624
• Massey Ferguson 5600 Series (iT4 2013-2016)
• MF 5608
• MF 5609
• MF 5610
• MF 5611
• MF 5612
• MF 5613

1. 1

   Visually inspect the wiring harness leading to the DEF tank heater coolant valve solenoid for chafed wires, melted insulation, or pinched lines.

2. 2

   Disconnect the harness at the solenoid and inspect the pins for corrosion, moisture ingress, or loose terminals.

3. 3

   Using a multimeter, check the supply and ground circuits for a short to battery voltage (which triggers the High Voltage condition).

4. 4

   Measure the internal resistance of the solenoid coil. If the coil is internally shorted (reading near 0 ohms) or completely open, the valve has failed.

1. 1

   Prep the Machine

   Park the tractor on a level surface, turn off the engine, remove the key, and disconnect the battery to prevent electrical shorts.

2. 2

   Locate the Valve

   Locate the DEF coolant flow control solenoid valve. It is typically spliced into the coolant lines near the DEF tank assembly.

3. 3

   Clamp the Lines

   Use hose pinch-off pliers to clamp the coolant supply and return lines on both sides of the valve. This prevents excessive engine coolant loss during removal.

4. 4

   Disconnect

   Unplug the electrical harness connector from the solenoid.

5. 5

   Remove the Valve

   Loosen the hose clamps securing the coolant lines to the valve, pull the hoses off, and unbolt the valve from its mounting bracket.

6. 6

   Install the New Valve

   Mount the new solenoid valve. Crucial step: Ensure the valve is facing the proper direction according to the coolant flow arrows stamped on the valve body.

7. 7

   Reassemble

   Reattach the coolant hoses, tighten the hose clamps, and remove the pinch-off pliers. Reconnect the electrical harness.

8. 8

   Refill and Test

   Top up the engine coolant reservoir to replace any lost fluid. Reconnect the battery. Use a diagnostic service tool to clear the active E3363.31 fault code and run a DEF system heater test (or pump priming routine) to command the valve open and verify the repair. Check for coolant leaks while the system is pressurized.