Fendt 04.1.01 – Enhanced Control / Transmission Control Unit (ECU): Acceleration ramp switch faulty

The system has detected a Signal fault from the acceleration ramp switch, meaning the control unit is receiving an implausible, missing, or out-of-range electrical signal from the button. This can also be caused by an 8.5 V supply fault to the control console.

• 309 Vario COM III
• 310 Vario COM III
• 311 Vario COM III
• 312 Vario COM III
• Fendt 300 Vario (including COM III)
• Fendt 400 Vario / Farmer 400 (including COM III)
• Fendt 700 Vario / Favorit 700 (including COM III)
• Fendt 800 Vario (including COM III)
• Fendt 900 Vario / Favorit 900 (including COM III)

1. 1

   Check the A013 PCB (microfuse board) Fuse 4 (or Fuse 5, depending on model) for an 8.5V supply failure

2. 2

   Inspect the acceleration ramp switch/button on the A036 control console mechanically to ensure it is not stuck, jammed with debris, or damaged

3. 3

   Inspect the wiring harness connecting the A036 control console to the main transmission/enhanced control ECU for chafed wires or loose connector pins

1. 1

   Power Down

   Turn off the tractor and disconnect the battery ground to prevent electrical spikes.

2. 2

   Fuse Replacement

   If A013 Fuse 4 is blown, replace it with a fuse of the exact same amperage. Reconnect the battery and turn the key on. If the fuse blows immediately, trace and repair the short to ground in the wiring harness leading to the A036 console.

3. 3

   Console Testing

   If the fuse is intact and the wiring tests good for continuity, the internal circuitry of the acceleration ramp switch has failed.

4. 4

   Component Replacement

   Remove the armrest/console trim, unplug the multi-pin connectors, and swap in a new control console keypad (A036).

5. 5

   Clear Codes

   Reassemble the console, power up the tractor, and use the FENDIAS diagnostic software (or the onboard terminal) to clear the stored 04.1.01 fault code.

6. 6

   Test Drive

   Operate the tractor to verify that it has exited emergency mode and that the acceleration ramp functions respond correctly.