Massey Ferguson E520217.31 – Engine Control Unit (ECU): Engine Module Internal Issue (ECU) / ECU internal fault 0110

The code indicates an internal failure within the Engine Control Unit. Specifically, official AGCO/Sisu Power engine manuals describe this as a 'Diagnostic fault check to report multiple errors while checking the complete MOCSOP ROM-memory (test of redundant shut-off paths).' This means the ECU's internal memory or safety shut-off logic has failed its self-test.

• 7616
• 5612
• 7622
• Interim Tier 4 (2012-2015)
• 7614
• 5611
• 7615
• 5610
• 5613
• 7620
• 5609
• 7618
• 5608
• 7619
• 7626
• 7624
• 4707
• 4708
• 4709
• 4710
• 5710 SL
• 5711 SL
• 5712 SL
• 5713 SL
• 7714
• 7715
• 7716
• 7716S
• 7718
• 7718S
• 7719
• 7720
• 7720S
• 7722
• 7722S
• 7724
• 7724S
• 7726
• 7726S

1. 1

   Verify battery voltage, inspect the main ECU ground strap, and check the wiring harness connectors at the ECU for corrosion or loose pins

2. 2

   Clear the fault codes using an AGCO Electronic Service Tool, cycle the key, and run the engine to see if the MOCSOP ROM-memory error returns

3. 3

   Check if there is a software update available for the tractor's EEM (Electronic Engine Management) system

1. 1

   Disconnect Power

   Turn off the ignition and disconnect the tractor's battery (negative terminal first) to prevent electrical spikes.

2. 2

   Locate the Engine ECU

   The ECU is typically mounted directly to the side of the AGCO Power engine block (often on vibration isolators).

3. 3

   Remove the ECU

   Carefully release the locking levers on the main wiring harness connectors and unplug them. Remove the mounting bolts securing the ECU to the engine block.

4. 4

   Install the New ECU

   Mount the replacement ECU and torque the bolts to OEM spec. Reconnect the wiring harnesses, ensuring the locking levers are fully seated.

5. 5

   Program the ECU

   A new or remanufactured ECU will be blank or require parameter matching. Connect the AGCO Electronic Service Tool (e.g., ACP0595980) to the tractor's diagnostic port. Flash the ECU with the correct software payload for the specific tractor model and engine serial number.

6. 6

   Test

   Reconnect the battery, turn the key to the ON position, and clear any historical codes. Start the engine and verify that E520217.31 does not return.