Massey Ferguson 3031.17 – Engine ECU: Issue With The Temperature Of The DEF Tank Temperature Sensor

The Engine Control Unit (ECU) has detected a problem with the signal from the DEF tank temperature sensor, indicating the signal is out of range, shorted, or has an open circuit. The ECU relies on this temperature data to prevent the DEF from freezing and to manage the Selective Catalytic Reduction (SCR) system effectively. Inaccurate or missing temperature readings can lead to SCR system malfunctions, increased emissions, and potentially force the engine to derate into a limp mode to prevent damage.

• 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
• 6612–6616
• 6712
• 6713
• 7614–7626
• 7714–7726S
• 9540
• 9560

1. 1

   Save and clear the error log to see if the code actively returns

2. 2

   If the DEF tank is surrounded by a protective cover, remove the cover to ensure accurate ambient/tank temperature measurement

3. 3

   Check for a loose contact in the sensor wiring

4. 4

   Inspect the sensor wiring harness for defects, such as open circuits or shorts to ground/battery

5. 5

   Ensure the DEF fluid is clean (32.5% urea solution), as contamination can cause erratic sensor readings or crystallization around the probe

1. 1

   Verify fault code status

   Turn the ignition ON with the engine OFF to verify if the 003031.17 code is active or stored.

2. 2

   Locate DEF tank temperature sensor

   Locate the DEF tank and access the DEF pump/header module where the temperature sensor is housed.

3. 3

   Inspect electrical connector

   Disconnect the electrical connector to the DEF tank temperature sensor. Inspect the pins for corrosion, moisture, or pushed-out terminals.

4. 4

   Verify wiring continuity

   Using a multimeter, verify continuity in the wiring harness between the sensor connector and the Engine ECU.

5. 5

   Determine sensor fault

   If the wiring and connectors are sound, the fault lies within the sensor itself ("The sensor is defective").

6. 6

   Replace DEF tank temperature sensor

   Remove and replace the DEF tank temperature sensor / DEF sending unit.

7. 7

   Clear fault codes and verify repair

   Reconnect the harness, turn the ignition on, and clear the fault codes using a diagnostic tool. Verify that the warning lamp turns off and the engine is no longer derated.