Fendt 0.0.1B – A002 ECU: ECU, enhanced control — TeachIn bus faulty - Master (Variotronic TI)

Teach-in data transfer fault indicating a CAN bus communication failure between the Variotronic TI (headland management/teach-in system) and the master control unit. The tractor will enter an emergency mode / auxiliary operation mode, restricting automated functions.

• 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 series
• Fendt 400 Vario / Farmer 400 series (409, 410, 411, 412, 413, 414, 415)
• Fendt 700 Vario / Favorit 700 series (711, 712, 714, 716, 718)
• Fendt 800 Vario series (815, 817, 818, 820)
• Fendt 900 Vario / Favorit 900 series (916, 920, 924, 926, 930)

1. 1

   Check CAN Bus Power Supply: The voltage supply for the CAN bus is routed through the A013 printed circuit board (the microfuse board). Check this board for blown fuses (specifically check fuses F039, F040, F041, F046, and F047, which are heavily associated with CAN bus and terminal power failures).

2. 2

   Inspect Wiring: Refer to Fendt wiring diagram Sheet 22 / 6 (Electronics voltage supply / Enhanced control bus). Check the physical CAN bus wiring between the A002 ECU and the A008 Variotronic Terminal for continuity, shorts to ground, or chafing.

3. 3

   Check ECU Voltage: Verify that the A002 ECU is receiving its proper basic signal voltage (U1) and that there are no 8.5V or 12V supply faults.

1. 1

   Access the A013 Fuse Board

   Locate the A013 printed circuit board and test all microfuses related to the CAN bus and the A002 ECU. Replace any blown fuses and re-test the system.

2. 2

   Inspect Connectors

   Disconnect the harnesses at the A002 Enhanced Control ECU and the A008 Variotronic Terminal. Inspect the pins for corrosion, moisture, or pushed-out terminals. Clean with contact cleaner and reseat.

3. 3

   Test the CAN Line

   Using a multimeter, measure the resistance across the CAN High and CAN Low pins to ensure the bus is intact and properly terminated.

4. 4

   Software/Reprogramming

   If the wiring and power supplies are intact, connect the FENDIAS diagnostic tool. You may need to perform an End-of-Line (EOL) reprogramming or flash the ECU with a new data record.

5. 5

   Component Replacement

   If EOL programming fails or the module is unresponsive, replace the A002 ECU. Note that a new A002 ECU will require EOL programming upon installation to match the tractor's specific equipment profile.