Fendt 6.1.0A – A004 Control Console: A004 - 'Active' key (only NA version) — Key / A004 signal fault

An electrical or mechanical signal fault originating from the 'Active' button on the tractor's main control console. The system registers this when the key's signal is implausible, commonly because the button has suffered an internal circuit failure, is physically stuck, or has been depressed for more than 30 seconds. This results in the Rear PTO being locked out and unable to be engaged.

• 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 Farmer 400 series (409, 410, 411, 412)
• Fendt Favorit 700 series (711, 712, 714, 716)
• Fendt Favorit 900 series (916, 920, 924, 926, 930)
• Fendt Vario COM III Series (300, 400, 700, 800, and 900 Vario)

1. 1

   Inspect the 'Active' key on the A004 control console for physical damage, sticking, or dirt/debris wedged in the membrane that might be preventing the button from releasing.

2. 2

   Verify the voltage supply for the CAN Bus by checking the A013 fuse board, specifically inspecting fuses F040 and F041, which supply power to the A004 console.

3. 3

   Connect the FENDIAS diagnostic tool to monitor the live state of the 'Active' key to see if it registers as permanently 'Pressed' without physical actuation.

4. 4

   Inspect the wiring harness and CAN bus connections between the A004 Control Console and the A002 (Enhanced Control ECU) for continuity or shorts.

1. 1

   Power Down

   Turn off the tractor and disconnect the battery before servicing electrical components.

2. 2

   Clear Debris

   If the button is physically sticking, carefully clean the edges of the 'Active' key with electrical contact cleaner.

3. 3

   Replace Fuses

   If the A004 console is unresponsive entirely, replace any blown fuses (F040, F041) on the A013 board.

4. 4

   Console Removal

   If the button has failed internally (a highly common issue as the membrane ages), the A004 control console must be removed from the right-hand armrest/side panel.

5. 5

   Repair or Replace

   Send the unit to a specialized agricultural electronics repair center (e.g., Ilgenfritz Mechatronics) to have the individual buttons/membrane repaired, or replace the entire A004 console with a new OEM unit.

6. 6

   Reassembly & Calibration

   Reinstall the repaired/new A004 console. Reconnect the battery.

7. 7

   Clear Codes

   Use the FENDIAS system to clear the 6.1.0A fault code.

8. 8

   Test

   Start the tractor and test the Rear PTO engagement to verify the fault is resolved and the PTO engages normally.