Fendt 01.1.B0 – A002 / A050: CAN-bus communication is restricted

There is a data transfer or initialization error between the tractor's main control unit and the Engine Control Unit (EDC), resulting in limited engine function (reduced engine power or emergency mode).

• 309 Vario COM III
• 310 Vario COM III
• 311 Vario COM III
• 312 Vario COM III
• Fendt 300 Vario series
• Fendt 400 Vario series
• Fendt 700 Vario series
• Fendt 800 Vario series
• Fendt 900 Vario series

1. 1

   Check the CAN bus wiring harness between the basic/enhanced control unit (A002/A050) and the engine control unit (A051) for chafing, corrosion, or broken wires.

2. 2

   Inspect the multi-pin connectors at both the A002/A050 and A051 ECUs. Look for pushed-out pins, moisture ingress, or poor terminal tension.

3. 3

   Verify the electronics voltage supply to the ECUs. Check the main fuse board (specifically A013) to ensure no blown fuses are interrupting the CAN bus power supply.

4. 4

   Connect the FENDIAS or SERDIA diagnostic tool to check if the EDC (A051) is reporting any internal faults or if it has completely dropped off the bus.

1. 1

   Disconnect Power

   Turn off the tractor and disconnect the battery before servicing the ECUs or wiring.

2. 2

   Repair Wiring/Connectors

   If the diagnostic checks reveal a physical break or short in the CAN bus wiring between A002/A050 and A051, splice in a wiring repair kit or replace the damaged connector terminals.

3. 3

   Module Replacement

   If the wiring tests perfectly (continuity and resistance are within spec) and power/ground are present, one of the control units (A050/A002 or A051) has likely suffered an internal CAN transceiver failure. Replace the faulty ECU.

4. 4

   EOL Programming

   If an ECU is replaced or if the memory was corrupted causing the communication restriction, the dealer must re-flash the control unit using the Fendt diagnostic software to match the tractor's specific parameters.

5. 5

   Clear Codes

   After repair and programming, clear the stored 01.1.B0 fault code from the A050/A002 memory and test drive the tractor to ensure full engine power is restored.