Fendt F.1.F0 – A002 ECU (Enhanced Control) or EDC / EMR (Engine Control Modules): A034 - Driving switch, CAN bus

CAN bus communication failure with the A034 Driving Switch (Joystick). Data transfer from the drive switch is faulty, or the hand throttle memory keys on the joystick have suffered an electrical fault. The tractor typically enters a restricted emergency operation mode, auxiliary control valves may cease to function, and the engine retains its last RPM speed.

• 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 Farmer 400
• Fendt Favorit 700 and 900
• Fendt 300 Vario (COM III)
• Fendt 400 Vario (including COM III)
• Fendt 700 Vario (including COM III)
• Fendt 800 Vario (including COM III)
• Fendt 900 Vario (including COM III)

1. 1

   Check fuse F047 on circuit board A013 for the joystick's CAN bus power supply

2. 2

   Inspect the CAN connection (Enhanced control BUS) wiring harness between the A002 ECU and the A034 Drive switch for continuity, shorts, or corrosion at the connector pins

3. 3

   Test the hand throttle memory keys and drive switch buttons on the joystick for physical damage, sticking, or internal electrical shorts

1. 1

   Isolate the Power Circuit

   Locate circuit board A013 and test fuse F047. If blown, replace it and re-test the tractor. If it blows again immediately, there is a short in the joystick or its wiring harness.

2. 2

   Harness Verification

   Disconnect the A034 Joystick and the A002 ECU. Use a multimeter to check the CAN-High and CAN-Low lines for proper resistance (typically 60 ohms across the bus) and ensure there is no short to ground or power. Repair any damaged wiring.

3. 3

   Replace the Component

   If the wiring harness is intact and the fuse is good, the internal CAN transceiver or the memory button circuit inside the A034 Driving Switch has failed. The joystick assembly cannot typically be repaired internally and must be replaced.

4. 4

   Post-Repair Calibration

   Install the new joystick, clear the fault codes via the terminal or EST diagnostic tool, and verify that auxiliary valves and throttle memory functions have been restored.