Fendt 04.1.19 – A050 - ECU, basic control unit: Error on reading-in throttle pedal parameters

The control unit is receiving invalid, uncalibrated, or conflicting data regarding the position of the foot throttle (accelerator) pedal. As a direct consequence, throttle pedal mode becomes impossible, and the tractor's TMS (Tractor Management System) is automatically switched off.

• 922 Vario COM III
• 924 Vario COM III
• 927 Vario COM III
• 930 Vario COM III
• 933 Vario COM III
• 936 Vario COM III
• Fendt 300 Vario series
• Fendt 400 Vario series
• Fendt 700 Vario series (including SCR / Tier 4 models)
• Fendt 800 Vario series
• Fendt 900 Vario series (COM III, S4, etc.)

1. 1

   Check the B055 Foot Throttle Sensor signal to determine if it is too high, too low, or absent

2. 2

   Verify the 8.5 V power supply to the B055 sensor (check Fuse 19 for a blown fuse)

3. 3

   Inspect the wiring harness and connectors between the B055 foot throttle sensor and the A050 Basic Control Unit for corrosion, shorts, or breaks

4. 4

   Check for accompanying EEPROM fault codes (such as F30/F31 or 08.1.A1) indicating the A050 ECU is failing to read/write to its internal memory

1. 1

   Resolve Electrical Faults

   If the 8.5V supply is missing or wiring is damaged, repair the harness or replace the relevant fuse (Fuse 19).

2. 2

   Replace the Sensor

   If the B055 sensor fails testing (e.g., distance between idle and full throttle reads too short or rotation angle is out of spec), physically replace the foot throttle rotary position sensor.

3. 3

   Recalibrate / EOL Programming

   Perform an EOL (End of Line) programming or run the specific calibration code for the foot throttle (often Calibration Code 4005) via the tractor's terminal to teach the A050 ECU the new idle and full-throttle parameters.

4. 4

   ECU Repair/Replacement

   If calibration fails to save (EEPROM error) or the A050 unit is internally defective, the A050 Basic Control Unit must be removed and sent to a specialized agricultural electronics repair service (e.g., Ilgenfritz Mechatronics) or replaced entirely.