Massey Ferguson 3031.1 – Engine Control Unit (ECU): Issue With The Temperature Of The DEF Tank Temperature Sensor. (ECU)

This code is triggered when the Engine Electronic Module (EEM) monitoring system detects that the temperature value reported by the Diesel Exhaust Fluid (DEF) tank temperature sensor is implausible or out of the expected range.

• 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

   Check for other active DTCs (such as CAN communication errors or DEF quality codes) that might indicate a broader harness issue

2. 2

   Inspect the wiring harness and sensor connector for loose contacts, chafing, breaks, or corrosion

3. 3

   Check the DEF tank cover (if equipped) to ensure accurate ambient temperature measurement and inspect the sensor housing

4. 4

   Save the error log, clear the fault code using a diagnostic tool, cycle the key, and retest to see if the fault returns immediately or during operation

1. 1

   Purge the System

   Turn off the ignition and wait for the DEF pump to finish its purge cycle (you will hear the pump reverse to pull fluid back into the tank). Do not disconnect the battery until this is complete.

2. 2

   Access the Tank

   Remove any protective shielding or covers surrounding the DEF tank.

3. 3

   Clean the Area

   Thoroughly clean the top of the DEF tank around the sensor header. The DEF system is highly sensitive to contamination; treat the area like a jet fuel filler to prevent dirt from falling into the tank.

4. 4

   Disconnect

   Unplug the electrical connector from the DEF tank sensor unit. Disconnect the heated DEF supply and return lines (be careful not to nick the O-rings).

5. 5

   Remove the Sensor

   Unscrew the locking ring or mounting bolts holding the DEF sensor unit in place and carefully pull the sender assembly out of the tank.

6. 6

   Install the New Sensor

   Insert the new DEF sensor unit, ensuring the sealing O-ring is properly seated to prevent dust and moisture ingress. Secure the locking ring/bolts.

7. 7

   Reconnect

   Reattach the heated DEF lines and the electrical connector.

8. 8

   Verify

   Turn the ignition on, clear the fault codes with a diagnostic tool, and monitor the DEF tank temperature live data to ensure it is reading a plausible value.