Fendt 0B.2.01 – A050 - ECU, basic control unit: Warning message on cancel TeachIn due to seat switch no longer being pressed.

An automated Variotronic TI (Teach-In / Headland Management) sequence was actively running or being recorded, and the sequence was aborted because the operator presence seat switch circuit opened. This happens if the operator stands up, bounces out of the seat over rough terrain, or if the seat switch/wiring fails intermittently.

• 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 (COM III, SCR, S4)
• Fendt 400 Vario (COM III)
• Fendt 500 Vario (SCR)
• Fendt 700 Vario (COM III, SCR, S4)
• Fendt 800 Vario (COM III, SCR)
• Fendt 900 Vario (COM III, SCR)

1. 1

   Confirm with the operator if they simply lifted their weight off the seat while a headland management sequence was running. If so, clear the code and explain the safety feature. No repair is necessary.

2. 2

   Test the seat switch function by sitting in the seat and observing the tractor's diagnostic terminal to see if the operator presence state flickers or drops out.

3. 3

   Inspect the wiring harness beneath the seat for pinched wires, chafing from the seat suspension movement, or loose/corroded connectors.

4. 4

   Disconnect the seat switch and test it for continuity and proper resistance using a multimeter (many Fendt Grammer seats use a specific 510/122 Ohm resistor network).

1. 1

   Power down tractor

   Turn off the ignition and disconnect the tractor's battery to prevent accidental short circuits.

2. 2

   Access the switch

   Remove the seat cushion by releasing the front clips or removing retaining screws under the front lip of the cushion to access the switch assembly.

3. 3

   Disconnect wiring

   Locate the seat switch assembly embedded in the cushion base or suspension frame and disconnect the electrical harness plug.

4. 4

   Remove and replace switch

   Unclip or unscrew the faulty switch. If the replacement switch requires the transfer of a rocker mechanism (e.g., Grammer rocker 1100731), swap it over to the new switch, then snap it into place.

5. 5

   Reassemble seat

   Reconnect the wiring harness, ensuring the cable is routed safely away from the scissor suspension pinch points, and reinstall the seat cushion.

6. 6

   Test system

   Reconnect the battery, start the tractor, engage a Variotronic TI sequence, and verify that the sequence completes without throwing the 0B.2.01 code while seated.