Fendt 5.1.9F – Instrument cluster: S034 - Engine coolant level switch / sensor Signal fault

Signal fault / Engine coolant level sensor defective. The system registers a loss of signal from the sensor, resulting in 'No further monitoring' of the engine coolant level.

• 409 Vario
• 410 Vario
• 411 Vario
• 412 Vario
• 711 Vario
• 712 Vario
• 714 Vario
• 715 Vario
• 716 Vario
• 717 Vario
• 718 Vario
• 916 Vario
• 920 Vario
• 924 Vario
• 926 Vario
• 930 Vario
• 411 Vario COM III
• 412 Vario COM III
• 413 Vario COM III
• 414 Vario COM III
• 415 Vario COM III
• 712 Vario COM III
• 714 Vario COM III
• 716 Vario COM III
• 718 Vario COM III
• 818 Vario COM III
• 820 Vario COM III
• Fendt 300 Vario (COM III)
• Fendt 400 Vario (COM III)
• Fendt 700 Vario (COM III)
• Favorit 700
• Fendt 800 Vario (COM III)
• Fendt 900 Vario (COM III)
• Favorit 900
• 916
• 920
• 924
• 926
• 930
• 936
• 939

1. 1

   Verify Coolant Level: Physically check the coolant expansion tank to ensure the fluid is within the specified range.

2. 2

   Inspect Wiring and Connections: Check the wiring harness and the electrical connector at the S034 switch for corrosion, broken wires, or loose pins. The signal fault often points to an open circuit or disconnected plug.

3. 3

   Circuit Testing: Refer to the 'Dashpanel' / 'Instrument cluster' circuit diagram (Sheet 35 in some EDC7 manuals) to test the continuity of the sensor's signal wire back to the instrument cluster.

4. 4

   Diagnostic Tool: Connect the Fendt SERDIA diagnostic tool to read the live status of the sensor and attempt to clear the fault code (FC:0025) to see if it returns immediately.

1. 1

   Preparation

   Ensure the tractor engine is completely cool to prevent burns and depressurize the cooling system by carefully loosening the expansion tank cap.

2. 2

   Disconnect

   Locate the S034 coolant level switch on the coolant expansion tank and disconnect its electrical connector.

3. 3

   Removal

   Remove the defective sensor. (Depending on the specific tank design, you may need to drain a small amount of coolant if the sensor is a 'wet' probe type rather than a dry-pocket reed switch).

4. 4

   Installation

   Install the new OEM coolant level sensor.

5. 5

   Reassembly

   Reconnect the electrical harness to the new sensor.

6. 6

   Fluid Check

   Top up the engine coolant to the correct setpoint level if any was lost during the swap.

7. 7

   Clear Codes

   Use the SERDIA diagnostic software to delete the error code from the system and verify that the dashpanel no longer displays the 5.1.9F warning.