Fendt 05.1.5B – A050 - ECU, basic control unit: S086 - Switch, brake wearing, right. Brake pad worn.

Triggered when the right brake wear indicator switch (S086) detects that the right brake pad has worn down to its minimum allowable thickness, actuating the switch.

• 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)
• 711 Vario
• Fendt 800 Vario (COM III)
• Fendt 800 Vario S4 Series
• Fendt 900 Vario (COM III)
• 916 Vario
• 919 Vario
• 922 Vario
• 924 Vario
• 927 Vario
• 930 Vario
• 933 Vario
• 936 Vario

1. 1

   Check ECU Voltage Supply: The A050 basic control unit supplies a basic signal voltage of 6.0 VDC to the switch.

2. 2

   Measure Signal Voltage: With the ignition ON, measure the signal voltage returning to the ECU (Pin 51 on connector X1402, Earth pin 45). 1.8 VDC: Brake pad is OK (switch is not actuated; internal resistance is 121 Ohms). 3.7 VDC: Brake pad is worn (switch is actuated; internal resistance is 510 Ohms). 0 VDC or 6.1 VDC: Indicates a short to ground or an open circuit (this usually triggers a related signal fault code, such as 05.1.59).

3. 3

   Physical Inspection: Visually inspect the right brake pads to confirm their thickness. If the pads have plenty of material left but the voltage reads 3.7 VDC, the S086 switch is stuck or faulty.

1. 1

   Safely park the tractor, turn off the engine, and support the machine to access the right-side trailer/service brake assembly.

2. 2

   Inspect the right brake pads and the physical condition of the S086 wear indicator switch.

3. 3

   If the brake pads are worn to the limit, replace the brake pads.

   Note: It is highly recommended to replace brake pads on both the left and right sides simultaneously to ensure even braking performance.

4. 4

   If the brake pads are thick but the switch is sending the "actuated" resistance value (510 Ohms / 3.7 VDC), replace the S086 brake wear switch.

5. 5

   Inspect the wiring harness between the S086 switch and the A050 ECU for any chafing or breaks.

6. 6

   Reassemble the brake components and adjust the brakes according to the service manual specifications.

7. 7

   Access the tractor's diagnostic menu to clear the stored fault codes from the memory and test drive to ensure code 05.1.5B does not return.