Fendt 7.1.09 – A004 Control Console: Front PTO automatic mode key — Key / A004 signal fault

The system has detected a signal fault or a CAN bus communication error (Bus fault A004 / A002) originating from the automatic mode key for the Front Power Take-Off (PTO). The automatic mode is immediately terminated, and the front PTO disengages to prevent unintended operation or damage.

• 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 Vario 409
• Fendt Farmer 400 Vario 410
• Fendt Farmer 400 Vario 411
• Fendt Farmer 400 Vario 412
• Fendt Favorit 700 Vario 711
• Fendt Favorit 700 Vario 712
• Fendt Favorit 700 Vario 714
• Fendt Favorit 700 Vario 716
• Fendt Favorit 900 Vario 916
• Fendt Favorit 900 Vario 920
• Fendt Favorit 900 Vario 924
• Fendt Favorit 900 Vario 926
• Fendt Favorit 900 Vario 930
• Fendt 700 Vario COM III
• Fendt 800 Vario COM III
• Fendt 900 Vario COM III

1. 1

   Check fuses F040 and F041 on the A013 fuse board for CAN Bus voltage supply.

2. 2

   Inspect the physical Front PTO automatic mode key on the A004 console to ensure it is not stuck, damaged, or suffering from a plausibility error.

3. 3

   Test CAN bus continuity between the A002 Transmission Control Module and the A004 Side Console (specifically Pin 26 Connector X031) for interruptions or short circuits.

4. 4

   Refer to the PTO circuit diagram in the workshop manual to trace the exact signal path.

1. 1

   Power Down

   Turn the ignition off and disconnect the battery to prevent electrical spikes during testing.

2. 2

   Fuse Replacement

   If fuses F040 or F041 on the A013 board are blown, replace them and retest the system. If they blow again immediately, trace the wiring harness for a short to ground.

3. 3

   Harness Repair

   If the continuity test between A002 and A004 reveals a break or high resistance, repair the damaged section of the CAN bus wiring harness or replace the affected connector.

4. 4

   Console Testing/Replacement

   If the wiring and fuses are intact, the fault lies within the A004 Control Console itself (often an internal RAM, EEPROM, or 8.5V failure that disables keypad inputs).

5. 5

   Fit New Console

   Remove the right-hand armrest panel to access the A004 console. Disconnect the multi-pin connectors and remove the faulty unit. Install the new A004 Control Console.

6. 6

   EOL Reprogramming

   A new A004 console or A002 module will require End-of-Line (EOL) reprogramming and calibration using the FENDIAS diagnostic laptop to pair the modules and restore PTO functionality.

7. 7

   Clear Codes

   Clear the 7.1.09 fault code from the memory and test the Front PTO automatic mode at a ground speed of more than 1 km/h to verify the repair.