Massey Ferguson 9024 – ECU: Water in Fuel Sensor Voltage Above Normal

The Engine Control Unit (ECU) has detected that the voltage from the water-in-fuel sensor is higher than the normal operating range. The ECU typically provides a 5-volt reference to this sensor. An abnormally high reading indicates an electrical circuit issue, such as an open circuit, a short to a power source, or an internal failure within the sensor itself. This condition may illuminate a maintenance or warning lamp on the instrument panel.

• 8600 Series
• 4607M
• 4608
• 4609
• 4609M
• 4610
• 4610M
• 4707
• 4708
• 4709
• 4710
• 5608
• 5609
• 5610
• 5611
• 5612
• 5613
• 5709
• 5710
• 5711
• 5712
• 5713
• 5S.115
• 5S.135
• 5S.145
• 6S.135
• 6S.145
• 6S.155
• 6S.165
• 6S.180
• 6711
• 6712
• 6713
• 7714
• 7715
• 7716
• 7718
• 7719
• 7720
• 7722
• 7724
• 7726
• 7S.155
• 7S.165
• 7S.180
• 7S.210
• 7614
• 7615
• 7616
• 7617
• 7618
• 7619
• 7620
• 7622
• 7624
• 7626
• 8727S
• 8730S
• 8732S
• 8735S
• 8737S
• 8740S
• 8S.205
• 8S.225
• 8S.245
• 8S.265
• 8S.285
• 8S.305

1. 1

   Record the exact fault code and check for any other active codes.

2. 2

   Drain the fuel filter or water separator bowl to verify if water is actually present (if significant water is present, the sensor may be functioning correctly and the issue is fuel contamination).

3. 3

   Visually inspect the water-in-fuel sensor, its connector, and the wiring harness for damage, corrosion (especially green or white powder), loose connections, or chafing against chassis/engine components.

4. 4

   Test the sensor's electrical connector with a multimeter to verify it is receiving the correct reference voltage (typically 5V) from the ECU and has a solid ground connection.

5. 5

   Measure the signal wire voltage with the key on and the sensor connected. An abnormally high voltage (near or at the reference voltage) when no water is present points to an internal sensor failure or an open in the ground or signal return circuit.

1. 1

   Drain fuel/water separator

   Safely drain the contents of the fuel/water separator into a clean, clear container to check for water contamination. Address any fuel quality issues first.

2. 2

   Clean connections

   If visual inspection reveals corrosion, disconnect the battery, unplug the sensor connector, and clean the terminals using an appropriate electrical contact cleaner. Ensure the connection is secure upon reassembly.

3. 3

   Test wiring continuity

   If connections are clean and the fault persists, perform a point-to-point continuity test on the wiring harness between the sensor connector and the ECU connector to rule out an open circuit or a short to power.

4. 4

   Replace the sensor

   If the wiring is confirmed to be intact and the sensor is receiving correct power and ground, but the signal voltage remains high, the sensor itself is likely faulty and should be replaced.

5. 5

   Clear codes and verify repair

   After replacing the sensor, clear the fault codes using a diagnostic tool. Start the engine and let it run for a few minutes to ensure the code does not return.