Fendt 15.1.6E – A050 - ECU, basic control unit: B066 - Sensor, wheel position (left); B068 - Sensor, wheel position (right) - Plausibility error

The tractor's front axle suspension system uses two rotary position sensors (B066 on the left and B068 on the right) to monitor the height and movement of the front axle. The control unit continuously calculates the mean value of the movements from both sensors to manage the suspension cylinders. A "plausibility error" means that the readings coming from the left and right sensors contradict each other, fall outside the expected physical range, or do not match the commanded suspension state.

• 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)
• Fendt 400 Vario (COM III)
• Fendt 700 Vario (COM III)
• Fendt 800 Vario (COM III)
• Fendt 900 Vario (COM III)
• Fendt 919
• Fendt 922
• Fendt 924
• Fendt 927
• Fendt 930
• Fendt 933
• Fendt 936

1. 1

   Check Power Supply: The B066 and B068 sensors operate on an 8.5 V supply. Verify the voltage at the sensor connectors.

2. 2

   Check Fuses: The 8.5 V supply is protected by fuses on the A013 board. Check Fuse 17 (supplies B066 - left) and Fuse 09 (supplies B068 - right).

3. 3

   Inspect Wiring: Check for signal faults, broken wires, or corrosion in the harness leading from the front axle to the A050 ECU (refer to circuit diagram Sheet 9).

4. 4

   Mechanical Inspection: Inspect the physical linkages connecting the sensors to the front axle. A bent linkage, loose mounting bracket, or packed mud/debris can cause the sensor to read an implausible angle.

5. 5

   FENDIAS Diagnostics: Use the FENDIAS diagnostic tool to view the live data for B066 and B068. Compare the voltage/angle readings as the suspension is manually raised and lowered to identify which sensor is dropping out or sticking.

1. 1

   Secure the Machine

   Park the tractor on level ground, lower all implements, and safely support the front axle to remove pressure from the suspension system.

2. 2

   Access the Sensors

   Locate the B066 (left) and B068 (right) sensors on the front axle suspension assembly.

3. 3

   Remove the Faulty Sensor

   Disconnect the electrical harness. Unbolt the sensor linkage from the axle and remove the sensor from its mounting bracket.

4. 4

   Install the New Sensor

   Mount the replacement sensor and reattach the mechanical linkage. Ensure the linkage moves freely without binding. Reconnect the electrical harness.

5. 5

   Calibration

   Because of mechanical and electrical tolerances, the new sensor(s) must be calibrated to the tractor. Enter the tractor's terminal/dashboard calibration menu for the front axle suspension and follow the on-screen prompts to teach the ECU the new upper and lower limits.

6. 6

   Clear Codes and Test

   Clear the 15.1.6E fault code from the memory. Start the tractor and cycle the suspension through its full range of motion (Raise/Lower/Lock) to verify the repair.