Fendt 08.1.25 – Rear EPC (Electronic Power Control): S071 - Switch, rapid lowering (Rapid lowering short circuit Ub+)

The control module has detected a short circuit to positive battery voltage (Ub+) on the circuit belonging to the rapid lowering switch, triggering a 'Control locked' state that disables the rapid lowering and automatic rear linkage functions.

• 309 Vario COM III
• 310 Vario COM III
• 311 Vario COM III
• 312 Vario COM III
• Fendt 200 V/F/P Vario series
• Fendt 300 Vario (including COM III)
• Fendt 400 Vario COM III
• Fendt 700 Vario COM III
• Fendt 800 Vario COM III
• Fendt 900 Vario COM III

1. 1

   Verify tractor's control voltage (many Fendt linkage systems operate on 16V, not 12V) before probing to avoid module damage.

2. 2

   Inspect the S071 switch (on right mudguard or main console) for physical damage, sticking buttons, or water ingress.

3. 3

   Check separation points/connectors (X1355, X1359, and X1360) for corrosion, moisture, or damaged pins bridging the circuit to power.

4. 4

   Test the wiring harness between the S071 switch and the Rear EPC module for a short to Ub+ (battery positive) using a multimeter.

1. 1

   Disconnect Power

   Turn off the tractor and disconnect the battery to prevent further electrical damage or accidental shorting during the repair.

2. 2

   Access the Switch

   Remove the necessary trim panels on the right mudguard or control console to access the rear of the S071 rapid lowering switch.

3. 3

   Disconnect and Isolate

   Unplug the switch at its separation points (X1355/X1359/X1360).

4. 4

   Test the Switch

   Check the switch internally for a short circuit using a multimeter. If the switch is internally shorted, it must be replaced.

5. 5

   Repair Wiring

   If the switch tests fine, trace the wiring harness back to the Rear EPC module. Locate the chafed wire or damaged connector causing the short to Ub+ and repair the wiring.

6. 6

   Install the New Part

   If the switch is faulty, install the replacement switch. Ensure the connector is clean and seated securely.

7. 7

   Clear Fault Codes

   Reconnect the battery and turn the ignition on. Use the Fendt terminal or a compatible diagnostic tool (e.g., TEXA, SERDIA) to clear the stored 08.1.25 fault code.

8. 8

   Operational Test

   Test the rear linkage lift and rapid lowering functions to confirm the repair is successful and the control lock has been lifted.