Massey Ferguson E520222.31 – Engine Control Unit (ECU): Engine Module Internal Issue (ECU)

MoCSOP (redundant stop test) Diagnostic error or Diagnostic fault check to report the error in undervoltage monitoring. The ECU has detected an internal hardware/software failure during its self-check routine, or it has detected an internal undervoltage condition.

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

1. 1

   Test the tractor's batteries and alternator for severe voltage drops during cranking or operation, which can trigger false internal ECU undervoltage faults

2. 2

   Check the engine main relay for sticking or early opening defects that could interrupt power to the ECU

3. 3

   Inspect the main wiring harness connectors at the Engine ECU for pushed-out pins, corrosion, or moisture ingress

4. 4

   Use a diagnostic tool to clear the code to determine if it is a historical glitch or a hard internal fault that returns upon key-on

1. 1

   Disconnect Power

   Turn off the battery disconnect switch or remove the negative battery cable to prevent electrical spikes.

2. 2

   Remove the ECU

   Locate the Engine ECU (typically mounted on the side of the engine block on SISU engines). Disconnect the large multi-pin connectors. Remove the mounting bolts and remove the module.

3. 3

   Software Update / Reflash

   Before replacing the hardware, a Massey Ferguson dealer should attempt to reflash the ECU with the latest software. Sometimes, MoCSOP logic errors are resolved via OEM software patches.

4. 4

   Replace the ECU

   If the module is bricked or physically damaged internally, install a new ECU.

5. 5

   Programming

   A new ECU is blank. A dealer technician must use the AGCO diagnostic tool (WinEEM / EDT) to program the new ECU with the tractor's specific engine file, VIN, and immobilizer data.