Fendt 05.1.58 – A050 - ECU, Basic Control Unit (EXT): S087 - Switch, brake wearing, left

Sensor or signal fault with the left brake wear indicator switch, indicating an irregular voltage, an open circuit, or a short circuit in the sensor's wiring.

• 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 series
• Fendt 400 Vario series
• Fendt 700 Vario series
• Fendt 800 Vario series
• Fendt 900 Vario series (e.g., 916, 920, 922, 924, 927, 930, 933, 936, 939)

1. 1

   Locate the S087 left brake wear indicator switch on the left brake assembly

2. 2

   Disconnect the switch and inspect the connector pins for corrosion, moisture, or damage

3. 3

   Measure the signal voltage at Pin 1 and Pin 2 of the harness connector with the key ON

4. 4

   Verify if the signal voltage from the A050 ECU reads approximately 6.0 to 6.1 VDC with the switch open (infinite resistance)

5. 5

   Verify if the signal voltage drops to 0 VDC with the switch closed (approx. 0 ohms resistance)

6. 6

   If voltages are missing or out of range, check for a wiring break or short between the S087 switch and the A050 Basic Control Unit

7. 7

   If voltages at the harness are correct but the fault persists, the switch is internally faulty

1. 1

   Safely secure the tractor

   Park on level ground, apply the handbrake, and turn the ignition off.

2. 2

   Access the switch

   Locate the left brake wear indicator switch (S087) on the left-hand side of the rear axle/brake housing.

3. 3

   Repair wiring (if applicable)

   If the diagnostic test revealed a voltage issue, trace the wiring harness back to the A050 ECU, repairing any chafed wires or broken connections.

4. 4

   Replace the switch (if applicable)

   If the switch failed the resistance test, unthread the faulty S087 switch from the brake assembly and install the replacement switch. Reconnect the electrical harness.

5. 5

   Clear the fault code

   Turn the ignition on. Use the tractor's Vario terminal to navigate to the fault code menu. Confirm, call up, and delete the stored fault code. (Note: Fault codes must be cleared individually; canceling a code from the main screen only hides it temporarily).

6. 6

   Test

   Actuate the brakes and perform a short test drive to ensure the code does not return.