Fendt 5.1.65 – Suspension Enhanced Diagnostic System: A004 - 'Suspension OFF / Lock' key — Fault in signal from key to A004.

This code indicates a communication or signal failure involving the front axle suspension lock switch. Specifically, the system detects a fault in the signal traveling from the 'Suspension OFF / Lock' key to the A004 Control Console. In tractors with a single e-box version, this code can also indicate a fault in the CAN/enhanced controls bus signal between the A004 Control Console and the A002 Transmission Control Module. The front axle suspension becomes non-operational. However, the tractor can continue to be driven without suspension functionality.

• 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 409
• Farmer 410
• Farmer 411
• Farmer 412
• Favorit 711
• Favorit 712
• Favorit 714
• Favorit 715
• Favorit 716
• Favorit 717
• Fendt 711 Vario
• Fendt 712 Vario
• Fendt 714 Vario
• Fendt 715 Vario
• Fendt 716 Vario
• Fendt 717 Vario
• Fendt 815 Vario
• Fendt 817 Vario
• Fendt 818 Vario
• Favorit 916
• Favorit 920
• Favorit 924
• Favorit 926
• Favorit 930
• Fendt 916 Vario
• Fendt 920 Vario
• Fendt 924 Vario
• Fendt 926 Vario
• Fendt 930 Vario
• 300 Vario COM III
• 400 Vario COM III
• 700 Vario COM III
• 800 Vario COM III
• 900 Vario COM III

1. 1

   Inspect the physical 'Suspension OFF / Lock' key on the A004 control console for sticking, physical damage, or liquid intrusion.

2. 2

   Verify the voltage supply for the CAN-Bus on fuse board A013 by checking fuses F040 and F041.

3. 3

   Test the wiring continuity and signal from the suspension key directly to the A004 Control Console.

4. 4

   For single e-box versions, check the CAN bus wiring harness between the A004 Control Console and the A002 Transmission Control Module for open circuits, shorts to ground, or corroded pins.

1. 1

   Power Down

   Turn off the tractor and disconnect the battery before servicing electrical components to prevent short circuits.

2. 2

   Fuse Replacement

   If fuses F040 or F041 on board A013 are blown, replace them with the correct amperage fuses and re-test the suspension switch.

3. 3

   Wiring Repair

   If continuity tests reveal a break or short in the wiring between the suspension switch and A004, or on the CAN bus between A004 and A002, repair or replace the affected section of the wiring harness.

4. 4

   Switch Replacement

   If the wiring is intact but the switch fails to send a signal when toggled, carefully pry out the faulty 'Suspension OFF / Lock' rocker switch from the console and plug in a replacement.

5. 5

   Console Repair/Replacement

   If the switch, wiring, and fuses are all good, but the A004 Control Console is failing to process the signal or communicate with A002, the A004 unit itself may have an internal fault requiring professional repair or replacement.

6. 6

   Clear Codes

   Reconnect the battery, turn on the tractor, and use the FENDIAS diagnostic tool (or the tractor's onboard terminal) to clear the 5.1.65 fault code and verify that the front axle suspension lock operates normally.