Fendt 06.1.45 – REAR PTO ENHANCED CONTROL: Plausibility error or Signal fault - B020 Sensor, rear PTO speed

The system detects that the PTO stub shaft speed sensor is registering a speed reading when the speed selection is in neutral and the PTO clutch is not engaged. This indicates a sensor/wiring fault, a failing PTO clutch disc pack, or an inoperative PTO brake.

• 922 Vario COM III
• 924 Vario COM III
• 927 Vario COM III
• 930 Vario COM III
• 933 Vario COM III
• 936 Vario COM III
• 200 Vario series (S3, V/F/P)
• 300 Vario series (COM III, SCR, S4)
• 400 Vario series
• 500 Vario series
• 700 Vario series (COM III, SCR, S4)
• 800 Vario series (COM III, SCR, S4)
• 900 Vario series (COM III, SCR, S4, Gen6)
• 1000 Vario series

1. 1

   Verify the 12V power supply to the sensor (check associated fuse, e.g., Fuse 32 or 35 on the A013 board).

2. 2

   Inspect the wiring harness and connectors leading to the B020 Hall-effect sensor for shorts to ground, open circuits, or corrosion.

3. 3

   Test the sensor signal output using a multimeter or diagnostic adapter box to check for erratic or stuck signals.

4. 4

   Inspect the PTO clutch disc pack and PTO brake mechanically to ensure proper separation and braking function.

1. 1

   Emergency Operation (Temporary Workaround)

   If the tractor is in the field, electric speed selection remains possible. The operator can bypass the fault and engage the PTO by pressing and holding the 'Engage PTO' (or PTO clutch ON/OFF) button in the cab for at least 5 seconds to enter emergency mode.

2. 2

   Access the Sensor

   Locate the B020 Hall-effect speed sensor on the rear PTO stub shaft housing.

3. 3

   Disconnect and Remove

   Disconnect the electrical harness from the sensor. Unbolt and remove the sensor from the housing.

4. 4

   Install Replacement

   Insert the new OEM speed sensor, ensuring any O-rings or seals are properly seated to prevent oil leaks.

5. 5

   Reconnect and Clear Codes

   Reconnect the wiring harness. Turn on the tractor, clear the fault codes via the terminal or FENDIAS diagnostic tool, and test the PTO engagement in neutral to ensure the plausibility error does not return.

6. 6

   Mechanical Repair (If necessary)

   If replacing the sensor does not clear the fault, the tractor will need to be split or the PTO housing opened to repair the seized PTO clutch pack or faulty PTO brake.