ECU 000097.03 – Water-in-Fuel Filter Signal Voltage High. John Deere Engine Control.

ECU 000097.03 (ECU 97.03)

Code: 000097.03

Shortcode: 97.03


The ECU 000097.03 (97.03) error code on John Deere equipment signals that the voltage from the water-in-fuel sensor is exceeding the upper limit specified for high sensor voltage. This usually indicates a short to 12 volts within the sensor’s circuitry. Such an issue can arise from faulty wiring, incorrect connections, or damage to the sensor itself, leading to erroneous signals that could mislead the detection system intended to protect the engine from water contamination in the fuel.


The engine control system may react to this high voltage signal by issuing warnings or entering a protective mode to prevent potential engine damage due to water in the fuel, based on the incorrect high sensor reading.


  • Inspect Sensor Wiring and Connections: Thoroughly examine the wiring and connections to the water-in-fuel sensor for any signs of damage, corrosion, or improper connections that could cause a short to 12 volts.
  • Test Sensor and Circuit: Utilize diagnostic tools to test the sensor and its circuit to isolate the source of the high voltage reading.
  • Replace Faulty Components: If the water-in-fuel sensor or any associated wiring is found to be defective, replace these with genuine John Deere parts to ensure accurate detection and functionality.
  • Reset the System and Confirm Operation: After making necessary repairs, reset the system to clear the error code and perform tests under various operating conditions to ensure the sensor operates correctly.


Regular maintenance and inspection of the fuel system’s sensors, including the water-in-fuel sensor, are crucial for reliable operation. Given that water in the fuel can cause significant engine damage, ensuring that the sensor system is functioning correctly is paramount. Additionally, maintaining clean and dry electrical connections is essential to avoid shorts and other electrical faults that could lead to false readings or sensor failures.

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