Massey Ferguson E3031.16 – Engine Control Unit (ECU) / EEM4: Issue With The Temperature Of The DEF Tank Temperature Sensor

The Electronic Engine Management (EEM) monitoring system has detected that the temperature value reported by the Diesel Exhaust Fluid (DEF) tank sensor is implausible or out of range. This invalid temperature signal will log an emission-related fault, trigger a warning lamp, and eventually induce an engine power derate.

• 7616
• 5612
• 7622
• Interim Tier 4 (2012-2015)
• 7614
• 5611
• 7615
• 5610
• 5613
• 7620
• 5609
• 7618
• 5608
• 7619
• 7626
• 7624
• MF 5608
• MF 5609
• MF 5610
• MF 5611
• MF 5612
• MF 5613
• MF 4707
• MF 4708
• MF 4709
• MF 4710

1. 1

   Check the Error Log: Connect a diagnostic service tool, save the error log, and clear the code to see if it is an active or stored (intermittent) fault.

2. 2

   Wiring & Connector Inspection: Inspect the electrical connector at the top of the DEF tank header unit. Look for loose contacts, corrosion, or pushed-out pins.

3. 3

   Harness Continuity: Test the wiring harness between the DEF tank sensor and the ECU for open circuits, shorts to ground, or shorts to power.

4. 4

   Live Data Verification: Use the diagnostic tool to read the live DEF tank temperature. Compare it to the ambient temperature on a cold engine. If the reading is pegged at an extreme (e.g., -40°C or +150°C), the sensor has failed internally.

5. 5

   Fluid Inspection: Ensure the DEF fluid is clean and uncontaminated. Dirt or diesel in the DEF tank can sometimes foul the sensor probes.

1. 1

   Turn off the tractor and disconnect the battery via the master disconnect switch.

2. 2

   Thoroughly clean the top of the DEF tank around the sensor header.

   This prevents any dirt or debris from falling into the tank during removal.

3. 3

   Disconnect the electrical connector from the DEF header unit.

4. 4

   Disconnect the DEF supply and return lines.

   These usually utilize quick-connect fittings. Note: Be careful not to nick the O-rings on the heated lines.

5. 5

   Remove the mounting bolts or the retaining lock-ring securing the header to the tank.

   Typically a 6-bolt pattern.

6. 6

   Carefully pull the old DEF sensor header assembly straight up and out of the tank.

7. 7

   Install the new DEF sensor header.

   Ensure the new rubber gasket/O-ring is seated properly to prevent contamination and leaks.

8. 8

   Reinstall the retaining bolts/ring, reconnect the fluid lines, and plug in the electrical connector.

9. 9

   Reconnect the battery, turn the key on, and use your diagnostic tool to clear the E3031.16 fault code from the ECU.

10. 10

    Run the engine and verify that the live DEF temperature data is now reading accurately and the code does not return.