Case IH F-628-31 - ECU – Engine Control Unit (ECU): ECU internal failure - Failure in accessing non-volatile memory read/write for at least one block

This indicates that the control module's internal memory (EEPROM) is failing to read or write data properly. This condition is typically caused by internal hardware degradation, severe electrical disturbances (voltage spikes), or a corrupted software configuration.

• MAGNUM AFS Connect
• Case IH Austoft 9000 series
• Case IH Austoft 9900 series
• Case IH Magnum AFS Connect series
• Magnum 250
• Magnum 310
• Magnum 340
• Case IH Axial-Flow series
• Axial-Flow 7230
• Axial-Flow 7240
• Axial-Flow 8230
• Axial-Flow 9230

1. 1

   Check battery and charging system voltage to rule out overvoltage or severe undervoltage that can disrupt EEPROM writing

2. 2

   Inspect main power supplies to the ECU (UB1, UB2, UB3) for shorts to ground or shorts to battery voltage

3. 3

   Check for external interference from aftermarket tuners, performance modules, or external devices triggering an ECU reset or CAN-bus errors

4. 4

   Connect the CNH Electronic Service Tool (EST) and attempt to clear the code and re-flash the ECU with the latest OEM software

1. 1

   Disconnect Power

   Turn off the master disconnect switch and disconnect the negative battery cable to prevent electrical arcing.

2. 2

   Remove the ECU

   Locate the Engine ECU (typically mounted directly to the engine block on FPT Cursor engines using vibration isolators).

3. 3

   Disconnect Harnesses

   Carefully release the locking levers on the main ECU wiring harness connectors and unplug them. Inspect the harness-side pins for corrosion or pushed-out pins.

4. 4

   Dismount

   Remove the mounting bolts securing the ECU to the engine block and remove the module.

5. 5

   Install New ECU

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

6. 6

   Reprogram

   Reconnect the battery. Connect the CNH EST diagnostic tool and flash the blank/reman ECU with the correct machine configuration, engine software, and injector trim codes specific to your machine's PIN/serial number.