Massey Ferguson E520218.31 – Engine Control Unit (ECU): Engine Module Internal Issue (ECU) - MOCSOP Loss of message synchronisation

The Engine Control Unit (ECU) failed its internal diagnostic redundant stop test because it lost synchronization in its internal messaging or CAN communication.

• 7616
• 5612
• 7622
• Interim Tier 4 (2012-2015)
• 7614
• 5611
• 7615
• 5610
• 5613
• 7620
• 5609
• 7618
• 5608
• 7619
• 7626
• 7624
• MF 7614
• MF 7615
• MF 7616
• MF 7618
• MF 7619
• MF 7620
• MF 7622
• MF 7624
• MF 7626
• MF 5608
• MF 5609
• MF 5610
• MF 5611
• MF 5612
• MF 5613

1. 1

   Check system voltage: Verify battery health and alternator output. Low voltage or voltage spikes can cause the ECU's internal processors to lose synchronization.

2. 2

   Inspect CAN-BUS lines: Check the CAN-BUS communication wiring harness connected to the ECU for continuity, high resistance, or shorts to ground/power.

3. 3

   Check ECU connectors: Inspect the main ECU harness connectors for moisture, corrosion, or backed-out pins.

4. 4

   Scan for related codes: Look for accompanying MOCSOP diagnostic errors (e.g., E520219.31, E520220.31, E520221.31) which further confirm an internal processing failure.

5. 5

   Clear and retest: Clear the fault codes and cycle the ignition. If the code immediately returns upon the system's self-test, the internal fault is hard-set.

1. 1

   Disconnect Power

   Disconnect the negative battery cable before servicing any electronic control modules.

2. 2

   Clean and Re-seat

   If diagnostic checks revealed dirty or loose connections at the ECU, clean the contacts with electronic cleaner, apply dielectric grease, re-seat the connectors, and test the machine.

3. 3

   Software Flash

   If the wiring is intact, the ECU has suffered a software corruption or hardware failure. Connect the AGCO dealer diagnostic tool and attempt to re-flash/update the ECU software.

4. 4

   Replace the ECU

   If the module will not take a flash or the code persists, the ECU hardware has failed and must be replaced.

5. 5

   Program the New Module

   Install the replacement ECU. A new ECU is blank and must be calibrated and programmed to the specific tractor's VIN/configuration using the AGCO CAN-BUS dealer service tool.