Fendt 01.1.7D – A051 - Engine Control Unit (ECU) / EDC control module: B055 - Rotary position sensor, combi-sensor - foot throttle pedal (faulty idle switch)

The system detects that the idle switch is malfunctioning or providing an implausible signal compared to the potentiometers. The tractor will typically retain the last speed setting, and advanced Tractor Management System (TMS) functions may be restricted or disabled.

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

1. 1

   Visual & Harness Inspection: Inspect the wiring harness and the single electrical connector at the B055 foot throttle pedal. Look for damaged pins, corrosion, or broken wires leading back to the A051 EDC control unit and A050 basic control unit.

2. 2

   Signal Congruence Check: Using a diagnostic terminal (FENDIAS), verify the voltage signals from the redundant potentiometers. Check for signal congruence between PIN 3 and PIN 6 of the combi-sensor.

3. 3

   Idle Switch Verification: Monitor the idle switch state in the diagnostic terminal. It should clearly toggle between 'Active' and 'Inactive' when the pedal is at rest versus slightly depressed. If the potentiometers show movement but the idle switch state does not change, the internal switch is confirmed faulty.

4. 4

   Voltage Supply Check: Verify that the sensor is receiving proper reference voltage from the tractor's electronics (A013 PCB).

1. 1

   Preparation

   Turn off the tractor and disconnect the battery to prevent electrical shorts.

2. 2

   Access the Sensor

   Locate the foot throttle pedal assembly on the cab floor. Remove the protective cover over the foot throttle, which is typically secured by a couple of screws.

3. 3

   Removal

   Disconnect the single electrical connector attached to the pedal. Remove the 4 mounting bolts securing the foot throttle assembly to the floor and remove the faulty unit.

4. 4

   Installation

   Position the new foot throttle pedal assembly and secure it with the 4 mounting bolts. Reconnect the electrical connector and reinstall the protective cover.

5. 5

   Power Up

   Reconnect the battery and turn the ignition on.

6. 6

   Mandatory Calibration

   Access the tractor's terminal and enter Calibration Code 4005 (Foot throttle pedal calibration). Set the foot throttle pedal to the idle (fully released) position. Accept the position using the 'Return' key on the terminal. If the calibration proceeds without errors, 'O.K.' will be displayed, and the new sensor settings will be saved to the EDC.