Massey Ferguson 9024 – ECU: Water in Fuel Sensor Supply Voltage Low

The Engine Control Unit (ECU) has detected that the supply voltage for the water-in-fuel sensor is below the normal expected level. This condition impairs the sensor's ability to accurately detect water in the fuel system, which is critical for preventing damage to high-pressure common rail fuel injection components. The fault typically indicates an issue with the sensor itself, the wiring harness, or the ECU's power supply circuit.

• 4600
• 4700
• 5600
• 5700
• 6700
• 7600
• 7700
• 8600
• 8700
• Sisu Tier 3 (AGCO Power) engines

1. 1

   Visually inspect the water-in-fuel sensor, electrical connector, and wiring harness for physical damage, corrosion, or chafing.

2. 2

   Drain the fuel/water separator bowl to check for significant water accumulation (a full bowl may cause true readings, though this code specifically points to a voltage issue).

3. 3

   With the sensor disconnected, turn ignition ON and verify the supply voltage (typically 5V or 12V reference) at the harness-side connector.

4. 4

   Check for good continuity to ground on the ground pin of the harness-side connector.

5. 5

   Measure the resistance across the pins on the disconnected sensor (typical resistance should be around 82kΩ); out-of-spec readings indicate a faulty sensor.

1. 1

   Drain fuel system

   Drain the fuel/water separator to remove any accumulated water.

2. 2

   Repair wiring and connectors

   If diagnostic checks revealed damage, repair or replace the affected wiring harness or connector. Ensure the connection is clean, free of corrosion, and secure.

3. 3

   Replace water-in-fuel sensor

   If the sensor failed the resistance test, unplug the electrical connector, unscrew the sensor from the bottom of the fuel filter housing, install the new sensor ensuring seals are seated, and reconnect.

4. 4

   Clear codes and retest

   Use a diagnostic tool to clear the fault code from the ECU's memory. Start the tractor and let it run to confirm the fault code does not reappear.