Massey Ferguson 3031.02 – Engine Control Unit (ECU) / EEM (Electronic Engine Management): Issue With The Temperature Of The DEF Tank Temperature Sensor

The engine management system has detected that the temperature value reported by the DEF tank temperature sensor is implausible, erratic, or has an abnormal rate of change. This triggers an emissions-related fault, illuminates the warning lamp, and eventually leads to an engine power derate.

• 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
• 7714S
• 7719S

1. 1

   Save and erase the error log using a diagnostic tool to see if it is a hard, active fault or an intermittent glitch

2. 2

   Inspect the wiring harness and connectors leading to the DEF tank header unit for loose contacts, chafing, or defective wiring

3. 3

   Monitor live data for the DEF tank temperature using a diagnostic tool and compare it to the actual ambient temperature of the tank

4. 4

   Inspect for physical damage, cracks, corrosion, or DEF crystallization around the DEF tank and sensor housing

5. 5

   Check DEF quality to ensure the fluid is not contaminated with water or diesel

1. 1

   Preparation

   Turn off the machine and disconnect the battery. Clean the area around the top of the DEF tank thoroughly to prevent dirt or debris from falling into the tank.

2. 2

   Disconnect Lines

   Carefully disconnect the electrical connector from the DEF header. Disconnect the DEF supply and return lines. Note: Cap the lines immediately to prevent contamination.

3. 3

   Remove the Header

   Remove the mounting bolts (often a 6-bolt flange) or unscrew the locking ring securing the DEF header to the tank.

4. 4

   Extract the Unit

   Carefully pull the old DEF header assembly out of the tank, taking care not to drip DEF on electrical components.

5. 5

   Install the New Unit

   Insert the new DEF header assembly into the tank. Ensure the new rubber O-ring or gasket is properly seated to prevent leaks and moisture ingress.

6. 6

   Reassembly

   Tighten the mounting bolts/ring to the manufacturer's specified torque. Reconnect the DEF fluid lines and the electrical connector.

7. 7

   Finalization

   Reconnect the battery. Use a diagnostic tool to clear the 003031.02 fault code. Turn the key on and verify that the live DEF temperature reading is now accurate and plausible.