Fendt 6.1.A1 – A004 Control Console: A004 - Rear PTO 'ON' key — Communication fault

The tractor's main control system has lost communication with the specific button/key used to engage the Rear Power Take-Off (PTO). This fault is specific to the Comfort Rear PTO or Enhanced Control circuit, and the normal in-cab PTO engagement button will not function.

• 409 Vario
• 410 Vario
• 411 Vario
• 412 Vario
• 711 Vario
• 712 Vario
• 714 Vario
• 715 Vario
• 716 Vario
• 717 Vario
• 718 Vario
• 916 Vario
• 920 Vario
• 924 Vario
• 926 Vario
• 930 Vario
• 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 (Chassis numbers 23/3001 and up)

1. 1

   Perform an emergency bypass test by pressing the emergency PTO key in the cab for 5 seconds or using the external rear PTO pushbuttons (S020) on the fenders to verify if mechanical components and ECU are functioning.

2. 2

   Inspect fuses F040 and F041 on the A013 printed circuit board, as a blown fuse will cause a total loss of communication with the console.

3. 3

   Inspect the wiring harness connecting the A004 Control Console to the main tractor harness, checking for CAN bus shorts to ground or broken wires.

4. 4

   Check for related CAN bus fault codes (e.g., 6.1.B0 or A004/A002 bus faults) which indicate a larger network failure rather than a single switch failure.

1. 1

   Power Down

   Turn off the tractor ignition and disconnect the battery to prevent electrical shorts during disassembly.

2. 2

   Access the Console

   Remove the side console panels or steering column cover (depending on the specific Vario model) to access the underside of the A004 Control Console.

3. 3

   Inspect Connections

   Disconnect the main harness connectors (e.g., Connector X033) from the A004 console. Clean the pins with contact cleaner and check for pushed-out pins or corrosion.

4. 4

   Replace the Switch/Console

   If the wiring and fuses (F040/F041) are intact, the internal RAM/EEPROM of the console or the physical PTO switch itself has failed. Depending on the exact console revision, you must either pop out and replace the individual 6-terminal PTO switch, or replace the entire A004 control console module.

5. 5

   Reassembly & EOL Programming

   Reconnect the harnesses and reinstall the console panels. Perform an EOL (End of Line) reprogramming using the FENDIAS diagnostic tool to marry the new components to the tractor's network.

6. 6

   Clear Codes

   Clear the 6.1.A1 fault code from the memory and test the PTO engagement.