Fendt 6.1.17 – A004 Control Console: A004 - 750 rpm speed selector key — Key / A004 signal fault

This code indicates a communication or electrical signal fault between the 750 rpm (540E) PTO speed selector button and the control console. The rear PTO speed cannot be modified or selected, and the PTO may fail to engage.

• 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
• Farmer 400 series
• Farmer 409
• Farmer 410
• Farmer 411
• Farmer 412
• Favorit 700 series
• Favorit 711
• Favorit 712
• Favorit 714
• Favorit 716
• Favorit 900 series
• Favorit 916
• Favorit 920
• Favorit 924
• Favorit 926
• Favorit 930
• Fendt 300 Vario series
• Fendt 400 Vario series
• Fendt 700 Vario series
• Fendt 800 Vario series
• Fendt 900 Vario series
• COM III generation models

1. 1

   Inspect the 750 rpm / 540E speed selector key on the console to ensure it is not mechanically stuck or jammed.

2. 2

   Consult the 'PTO's' circuit diagram for your specific chassis number.

3. 3

   Test the electrical signal continuity from the 750 rpm speed selector key to the A004 control console to rule out a broken wire or loose connector.

4. 4

   Verify that the A004 control console is receiving proper CAN-Bus voltage (supplied via fuse board A013; fuses F040, F041) to ensure the module is not experiencing a broader power failure.

1. 1

   Power Down

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

2. 2

   Access the Console

   Carefully disassemble the armrest/side panel to access the underside of the A004 control console where the PTO speed selector switches are housed.

3. 3

   Inspect and Test the Switch

   Disconnect the wiring harness from the 750 rpm (540E) speed selector switch. Use a multimeter to test the switch for proper open/closed continuity when pressed.

4. 4

   Replace the Switch (If Faulty)

   If the switch fails the continuity test or is mechanically broken, replace the individual switch component.

5. 5

   Inspect the Harness

   If the switch tests good, inspect the wiring harness connecting the switch to the A004 main board. Look for pinched wires, chafing, or corroded pins. Repair any damaged wiring.

6. 6

   Address the A004 Module (If Necessary)

   If both the switch and the wiring are in perfect condition, the internal circuitry of the A004 control console is likely faulty. The console will need to be removed and either sent to a specialized agricultural electronics repair facility or replaced entirely.

7. 7

   Reassembly and Clearing Codes

   Reconnect all components and restore battery power. Use the FENDIAS diagnostic system or the tractor's onboard terminal to clear the inactive fault code. Test the PTO speed selection to confirm the repair.