Fendt 02.1.E0 – A050 / A039: Faulty CAN communication between e-box and CAN joystick.

The main tractor control unit has lost its Controller Area Network (CAN) data link with the joystick located on the multifunction armrest. When this occurs, the tractor will typically restrict operations, resulting in non-operational functions, loss of implement control, or emergency mode.

• 922 Vario COM III
• 924 Vario COM III
• 927 Vario COM III
• 930 Vario COM III
• 933 Vario COM III
• 936 Vario COM III
• 300 Vario (COM III) (e.g., 312)
• 400 Vario (COM III) (e.g., 409, 410, 411, 412)
• 700 Vario (COM III & SCR) (e.g., 711, 712, 714, 715, 716, 717)
• 800 Vario (COM III & SCR) (e.g., 815, 817, 818)
• 900 Vario (COM III & SCR) (e.g., 916, 920, 924, 926, 930, 936)

1. 1

   Inspect the wiring harness and connectors running between the A039 Multifunction Armrest and the A050 Basic Control Unit for chafing, pinched wires, corrosion, or backed-out pins.

2. 2

   Test the CAN bus circuit for continuity, resistance (should be approx. 60 ohms across CAN High and CAN Low with batteries disconnected), and check for shorts to ground or power.

3. 3

   Fendt OEM procedures recommend using a 160-pin adapter box to test the inputs and outputs of both the A039 and A050 modules to isolate the communication break.

4. 4

   Verify that the A039 MFA and the CAN joystick are receiving proper operating voltage and have a clean ground connection.

1. 1

   Disconnect power

   Turn off the ignition and disconnect the tractor's battery to prevent electrical spikes.

2. 2

   Repair wiring harness

   If diagnostic checks reveal a broken wire or damaged connector pin in the harness between the A050 and A039, repair the wiring harness using OEM-approved splicing methods or replace the damaged connector.

3. 3

   Replace CAN joystick

   If the wiring is completely intact and tests perfectly, the CAN joystick hardware inside the A039 MFA is likely defective. Remove the armrest covers, disconnect the joystick harness, and install a replacement CAN joystick.

4. 4

   Replace or repair A050 ECU

   If the joystick is ruled out, the A050 Basic Control Unit itself may have a failed CAN transceiver. The A050 will need to be replaced or sent to an agricultural electronics specialist for board-level repair.

5. 5

   Perform EOL programming

   Reconnect the battery. If the A050 ECU or major MFA components are replaced, Fendt requires End of Line (EOL) programming using the FENDIAS diagnostic tool to pair the modules and restore functionality.

6. 6

   Clear codes and test

   Clear the stored 02.1.E0 fault code and test all joystick and valve operations to confirm the repair.