Massey Ferguson 520249.31 – Engine Control Unit (ECU) / EEM4: Engine Controller Internal Error

ECU internal fault 0125 or Reported SPI and COM-Errors of a Cy146, indicating a critical internal hardware or communication failure within the engine's main computer.

• 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
• Massey Ferguson 7700 Series
• MF 7722
• Massey Ferguson 8600 Series

1. 1

   Connect the AGCO Electronic Diagnostic Tool (EDT) / WinEEM4 service tool and verify the original EEM4 unit is running the latest software version, as outdated or corrupted software can trigger false internal errors.

2. 2

   Review the engine service parameters on the 'Configuration' page for any secondary leads to the problem.

3. 3

   Perform a temporary swap test: Connect a known-good temporary EEM4 unit, load the model-specific software, and use the EDT function 'Bypass Specification Mismatch' to override temporary errors. If the engine runs normally, the original ECU is confirmed faulty.

1. 1

   Connect EDT device

   Connect the EDT device to the tractor and select the correct tractor model and options (e.g., turbine clutch presence).

2. 2

   Save engine log

   Open the 'Diagnostic Test' page, select 'Save & Upload Engine Log', and save the engine log information to your desktop.

3. 3

   Save IQA codes

   Open the 'Calibration' tab and check the IQA codes (Injector Quantity Adjustment) from the 'Injector Calibration' function. Save these codes for later use.

4. 4

   Initiate ECU replacement

   Open 'Configuration', select 'Engine ECU Replacement', and initiate the process.

5. 5

   Power down tractor

   Switch the engine ignition to OFF. Wait at least 2 minutes until the main power relay clicks off completely. If the tractor has a main battery disconnect switch, turn it off and wait another 2 minutes.

6. 6

   Remove faulty ECU

   Disconnect the main wiring harnesses and remove the faulty EEM4 unit.

7. 7

   Install new ECU

   Install the new EEM4 unit and reconnect the harnesses.

8. 8

   Load software

   Turn the power back on, connect the EDT, and load the latest model-specific EEM4 software.

9. 9

   Write IQA codes and test

   Write the saved IQA codes to the new ECU and test all engine functions.