Fendt 1.1.03 – Engine Control Unit (ECU) / EDC / EMR: Foot throttle potentiometer plausibility error

The tractor's computer is detecting that the signals from the redundant tracks of the accelerator pedal position sensor do not match. The tractor will enter a restricted operating mode (limp mode), the accelerator pedal will stop functioning, and engine speed control will be limited to manual hand throttle operation or memory buttons.

• 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
• Farmer 409 Vario
• Farmer 410 Vario
• Farmer 411 Vario
• Farmer 412 Vario
• Favorit 711 Vario
• Favorit 712 Vario
• Favorit 714 Vario
• Favorit 715 Vario
• Favorit 716 Vario
• Favorit 717 Vario
• Favorit 916 Vario
• Favorit 920 Vario
• Favorit 924 Vario
• Favorit 926 Vario
• Favorit 930 Vario
• 815 Vario
• 817 Vario
• 818 Vario
• 300 Vario series

1. 1

   Inspect the wiring harness leading to the foot throttle sensor (B029, B038, or B055) for chafing, breaks, or short circuits. Disconnect the sensor and check the connector pins for corrosion or moisture.

2. 2

   Verify that the sensor is receiving a stable 12V reference voltage from the ECU. Check the A013 printed circuit board (microfuses) which powers the tractor electronics.

3. 3

   Monitor the live voltage values of the two potentiometers while slowly depressing the pedal using the FENDIAS diagnostic tool or the tractor's onboard terminal diagnostics. Look for dead spots, erratic voltage spikes, or a complete dropout on one of the tracks.

1. 1

   Turn off the tractor ignition and disconnect the battery.

   Ensure the machine is powered down before beginning the repair.

2. 2

   Locate the foot throttle assembly on the cab floor and remove the protective cover.

   The cover is usually secured by a couple of screws.

3. 3

   Disconnect the single electrical connector attached to the pedal assembly.

   Carefully unplug the harness from the sensor.

4. 4

   Remove the 4 bolts securing the foot throttle to the floor and remove the faulty unit.

   Take out the old pedal assembly.

5. 5

   Install the new foot throttle assembly and secure it with the 4 mounting bolts.

   Mount the replacement unit securely to the cab floor.

6. 6

   Reconnect the electrical connector and reinstall the protective cover.

   Ensure the connector is fully seated and the cover is fastened.

7. 7

   Reconnect the battery and turn on the ignition.

   Restore power to the tractor.

8. 8

   Calibrate the new foot throttle.

   This can often be carried out by the operator through the terminal (using calibration code '4005' for TRANSMISSION, AUTOMATIC MAXIMUM OUTPUT CONTROL) or via the FENDIAS diagnostic software.

9. 9

   Clear the stored fault codes and test drive the tractor.

   Ensure the accelerator pedal functions normally and the restricted operating mode is lifted.