Fendt 4.1.B4 – Transmission Control Unit / Tractor Management System (TMS): Sensor, engine 1 — Input parameter values for plausibility monitoring are incorrect.

The control unit is receiving an implausible signal from the primary engine speed sensor (B010). When this occurs, the system defaults to stored standard parameters so that the plausibility monitoring system remains functional. The tractor will typically allow continuation in emergency mode, but the fault requires attention and subsequent system reprogramming.

• 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
• 300 Vario Series (COM III)
• 815 Vario
• 817 Vario
• 818 Vario

1. 1

   Verify the 12V power supply to the sensor (often routed through the A013 fuse board, check fuses 11 or 33 depending on the model)

2. 2

   Inspect the wiring harness and connectors between the B010 sensor and the transmission control module for chafing, shorts, or corrosion

3. 3

   Compare live RPM readings of Engine Sensor 1 (B010) and Engine Sensor 2 (B011) using the FENDIAS diagnostic tool to confirm the plausibility mismatch

1. 1

   Locate the Sensor

   Park the tractor on a level surface, turn off the engine, and engage the parking brake. Locate the B010 Engine Speed Sensor 1 on the top left rear of the engine.

2. 2

   Remove the Sensor

   Disconnect the electrical harness connector from the B010 sensor. Remove the retaining bolt(s) and carefully pull the sensor out of its mounting port.

3. 3

   Install the New Sensor

   Clean the mounting surface. Insert the new OEM speed sensor, secure the retaining bolt to the manufacturer's torque specification, and reconnect the electrical harness.

4. 4

   Perform EOL Reprogramming

   Connect the FENDIAS diagnostic laptop to clear the fault, recalibrate the sensor parameters, and restore full Tractor Management System (TMS) functionality.