Massey Ferguson 3031.11 – Engine Control Unit (ECU) / EEM: Issue With The Temperature Of The DEF Tank Temperature Sensor

The system has performed a plausibility check and determined that the signal from the urea (DEF) tank temperature sensor is 'not plausible'. This means the sensor is reporting a fluid temperature that is either too high or too low compared to the expected ambient conditions, or the signal is erratic. If left unresolved, this emission-related fault will eventually trigger an engine power derate.

• 4710
• 7724S
• 5712SL
• 7722S
• 7722
• 5713SL
• 7720S
• 7716
• 7718
• T4
• 7715
• 5710SL
• 7726
• 4708
• 7726S
• 4707
• 4709
• 5711SL
• 7718S
• 7719
• 7714
• 7716S
• T4 (2015-2021)
• 7720
• Tier 4 (2015-2021)
• 7715S
• 7724
• 4608
• 4609
• 4610
• 5608
• 5609
• 5610
• 5611
• 5612
• 5613
• 6612
• 6613
• 6614
• 6615
• 6616
• 6712
• 6713
• 7614
• 7615
• 7616
• 7617
• 7618
• 7619
• 7620
• 7621
• 7622
• 7623
• 7624
• 7625
• 7626
• 7717
• 7721
• 7723
• 7725
• 8600 Series
• 8700 Series
• 9540
• 9560

1. 1

   Check for a loose contact in the sensor wiring harness at the DEF tank

2. 2

   Inspect the wiring harness between the DEF tank sensor and the ECU for chafing, shorts to ground, or open circuits

3. 3

   If the DEF tank is surrounded by a protective cover or shield, remove the cover to ensure accurate ambient temperature measurement and to inspect the tank neck

4. 4

   Ensure the DEF tank is not empty and that the fluid is not contaminated (which can sometimes cause erratic sensor readings)

5. 5

   Turn the ignition ON with the engine OFF to see if the code is active or stored

1. 1

   Access the DEF Tank

   Locate the DEF tank and thoroughly clean the area around the sending unit to prevent dirt from falling into the tank.

2. 2

   Disconnect the Harness

   Unplug the electrical connector from the DEF tank sensor module.

3. 3

   Test the Circuit

   Use a multimeter to verify that the sensor is receiving the correct 5V reference voltage from the ECU.

4. 4

   Replace the Sensor

   If the wiring is sound but the plausibility fault remains active, the temperature sensor (which is often integrated into the DEF level/quality sending unit) is defective and must be replaced. Remove the mounting ring/bolts, pull the old sensor assembly out, and install the new unit with a new O-ring.

5. 5

   Clear Codes

   Once the repair is complete, you must save the error log and then erase the fault codes from the EEM using a diagnostic service tool.