Fendt 4.1.06 (mech. engine control) – Transmission Control Module (EST Control Module A002): Target engine speed position sensor — Signal fault

The control unit is receiving an invalid signal (either too high, too low, or missing) from the pedal potentiometer. Because the system cannot accurately determine the operator's requested engine speed, the tractor will restrict operations and default to an emergency mode (auxiliary operation only).

• 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
• Fendt Farmer 400 series
• Fendt Favorit 700 series
• Fendt Favorit 900 series
• Fendt 300, 400, 700, 800, and 900 Vario COM III series

1. 1

   Check fuses on the A013 fuse board (specifically Fuse 4 or Fuse 14) for a blown fuse causing loss of 8.5V supply

2. 2

   Verify sensor supply voltage at the B018 sensor connector (should be 8.5V reference voltage)

3. 3

   Inspect the wiring harness between the B018 sensor and the EST Control Module (A002) for chafing, broken wires, or corroded pins

4. 4

   Monitor live data for the B018 sensor using the FENDIAS diagnostic tool to check for drifting, dropping out, or out-of-range signals

1. 1

   Power Down

   Turn off the tractor ignition and remove the key.

2. 2

   Fuse Replacement

   Locate the A013 printed circuit board (fuse board). Inspect Fuse 4 (and Fuse 14). If blown, replace it with a fuse of the correct amperage. If the fuse blows again immediately upon startup, there is a short to ground in the sensor wiring.

3. 3

   Access the Sensor

   Locate the B018 Target engine speed position sensor, which is mounted on the accelerator pedal assembly.

4. 4

   Remove the Faulty Sensor

   Disconnect the electrical harness connector from the sensor. Unbolt the sensor from the pedal linkage/bracket.

5. 5

   Install the New Sensor

   Mount the replacement B018 sensor to the pedal assembly and reconnect the electrical harness.

6. 6

   Clear Codes and Calibrate

   Turn the ignition on. Clear the stored 4.1.06 fault code via the tractor's terminal or FENDIAS. Depending on the exact model, you may need to perform a pedal calibration routine (e.g., calibration code 4005) so the ECU learns the new zero and maximum throttle positions.

7. 7

   Test Operation

   Test the accelerator pedal to ensure full RPM range is achieved and the tractor no longer defaults to emergency mode.