Fendt 1.2.B2 – A051 (EDC 7) / A020 (Pump Control): CAN message, no engine protection mechanism / Pump control unit fault

On COM III tractors, the engine control unit is missing a critical CAN bus message related to engine protection parameters. On older tractors, the pump control unit (EDC) identified a fault during a self-diagnostic test, resulting in reduced engine 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 300 Vario (COM III)
• Fendt 400 Vario (COM III)
• Farmer 400
• Fendt 700 Vario (COM III)
• Favorit 700
• Fendt 800 Vario (COM III)
• Fendt 900 Vario (COM III)
• Favorit 900

1. 1

   Connect FENDIAS or SERDIA diagnostic tool to read exact sub-codes (e.g., FC:006A) and verify if the fault is active or stored.

2. 2

   Test the CAN bus network resistance across CAN High and CAN Low pins (should read exactly 60 Ohms; 120 Ohms indicates a wiring break or failed terminating resistor).

3. 3

   Check the voltage level of the CAN lines (should be around 2.5V; 0 VDC indicates short to ground, 4+ VDC indicates short to power).

4. 4

   Inspect the wiring harness between the A002 (Enhanced Control ECU) and the A051 (Engine Control Unit EDC 7) for chafing, corrosion, or loose connector pins.

5. 5

   Verify that the A051 EDC 7 module is receiving proper operating voltage and has a clean ground connection.

1. 1

   Clear the code

   Use the SERDIA diagnostic software to delete the error (FC:006A).

2. 2

   Repair CAN bus wiring

   If the code immediately returns, isolate the CAN bus wiring between the tractor's main harness and the A051 ECU. Repair any broken wires or replace damaged connector pins.

3. 3

   Address terminating resistors

   If the CAN resistance check yielded 120 Ohms, locate and replace the faulty CAN terminating resistor.

4. 4

   Repair or replace ECU

   If the wiring and CAN network are perfectly intact but the A051 module still fails to process the engine protection CAN messages (or fails its internal self-diagnostic test on older models), remove the EDC 7 unit and either send it to a specialized agricultural electronics repair facility or replace it.

5. 5

   Perform EOL programming

   If a new or replacement EDC 7 ECU is installed, it must undergo EOL (End of Line) programming using FENDIAS to sync the immobilizer (A077) and configure the specific engine parameters.