Fendt 08.1.14 – Rear EPC (Electronic Power Control) module: Signal fault or faulty button related to the external rear power lift raise buttons

The system has detected a signal line fault or a key fault related to the external rear power lift raise buttons (S027 for the right-hand side, S029 for the left-hand side). As a safety consequence, the electrohydraulic lifting gear control is locked, and the button is rendered inoperable until the next trouble-free cold start.

• 309 Vario COM III
• 310 Vario COM III
• 311 Vario COM III
• 312 Vario COM III
• 300 Vario
• Farmer 400
• Favorit 700
• Favorit 900 Vario COM III

1. 1

   Inspect the external rear power lift raise buttons (S027 on the right rear fender, S029 on the left rear fender) for physical damage, sticking, or moisture ingress.

2. 2

   Test the signal line and earth connections for continuity and check for any shorts in the wiring harness between the buttons and the basic control unit ECU (A050).

3. 3

   Perform a resistance/signal test on the buttons to verify if the switch contacts are failing internally.

4. 4

   Check for stable voltage supply to the rear EPC control module.

1. 1

   Ensure the tractor is stationary, the engine is turned off, and the key is removed for safety.

   Safety precaution before starting repair.

2. 2

   Access the faulty external raise button (S027 or S029) located on the rear fender.

   Locate the switch on the respective rear fender.

3. 3

   Disconnect the 4-pin electrical connector from the back of the switch.

   Carefully unplug the connector.

4. 4

   Remove the faulty switch from its mounting housing.

   Extract the old switch.

5. 5

   Clean the electrical connector and apply a small amount of dielectric grease to prevent future moisture issues.

   Preparation for the new switch installation.

6. 6

   Install the new replacement switch and reconnect the wiring harness.

   Fit the new switch into the housing and plug in the 4-pin connector.

7. 7

   Clear the stored fault codes from the terminal.

   Remove the fault code from the system memory.

8. 8

   Perform a cold start (turn the tractor completely off, wait, and restart) to reset the locked control state and verify that the rear power lift operates correctly.

   Final verification to ensure the system is unlocked and functioning.