Fendt 1.2.B5 – A051 - Engine Control Unit (EDC 7) / A020 - Pump Control Unit: CAN-message missing / Fault during pump control unit self-diagnostic test

Indicates a communication or internal memory error related to the engine management system. The connection between the control unit and the injection pump is interrupted, causing the tractor to default to a derated state with reduced engine speed and power.

• 411 Vario COM III
• 412 Vario COM III
• 413 Vario COM III
• 414 Vario COM III
• 415 Vario COM III
• 712 Vario COM III
• 714 Vario COM III
• 716 Vario COM III
• 718 Vario COM III
• 818 Vario COM III
• 820 Vario COM III
• Fendt 400 Vario COM III
• Fendt 700 Vario COM III
• Fendt 800 Vario COM III
• Fendt 900 Vario COM III (916, 920, 924, 926, 930, 933, 936)

1. 1

   Check the CAN bus wiring harness between the A051 Engine ECU and the A020 Pump Control Unit (refer to Wiring diagram Sheet 36).

2. 2

   Inspect the wiring for breaks, short circuits to battery/earth, or loose connector pins at both the ECU and the injection pump.

3. 3

   Connect the Fendt SERDIA diagnostic software to the diagnostic connector (X412) to read the specific sub-fault code (FC:0071 is associated with the missing CAN message).

4. 4

   Verify if the pump control unit is failing its self-diagnostic test (EEPROM checksum error).

1. 1

   Isolate the Wiring

   If the diagnostic checks reveal a broken wire or short in the CAN bus lines (per Wiring diagram Sheet 36), repair or replace the affected section of the engine wiring harness.

2. 2

   Address the Pump Control Unit

   If the wiring is intact but the A020 Pump Control Unit is reporting an EEPROM checksum fault, the pump control unit or the entire injection pump assembly must be repaired, reprogrammed, or replaced.

3. 3

   Address the Engine ECU

   If the pump control unit is functioning but the A051 Engine ECU (EDC 7) is failing to process CAN messages, the ECU may require an EOL (End of Line) reprogramming or replacement.

4. 4

   Clear Fault Codes

   Fault codes stored in the A051 Engine ECU MUST be deleted using the SERDIA diagnostic software, as they cannot be cleared via the tractor's instrument panel buttons.