Massey Ferguson 94.03 – ECU (Engine Control Unit): Fuel Filter Pressure Sensor High Voltage / Low-Pressure Fuel Signal Out of Range High

This code indicates an electrical issue where the signal voltage from the low-pressure fuel sensor (fuel filter pressure sensor) exceeds the maximum expected threshold (typically over 4.0V - 4.5V for more than a few seconds). This usually points to a short circuit to power, an open ground circuit, or a completely failed sensor, rather than an actual mechanical fuel pressure issue.

• 4710
• 7724S
• 5712SL
• Interim Tier 4 (2012-2015)
• 7722
• 7722S
• 7615
• 5613
• 5713SL
• 7720S
• 7716
• 7718
• T4
• 7715
• 5710SL
• 7726
• 7616
• 7618
• 5608
• 4708
• 7619
• 7626
• 7726S
• 7624
• 4707
• 4709
• 5711SL
• 7614
• 7718S
• 5610
• 7620
• 7719
• 7714
• 7716S
• T4 (2015-2021)
• 5612
• 7622
• 7720
• Tier 4 (2015-2021)
• 5611
• 7715S
• 5609
• 7724
• 7600 Series
• 7700 Series
• 8700 Series

1. 1

   Locate the fuel filter pressure sensor (typically mounted on or near the primary fuel filter housing/lift pump) and inspect the wiring harness for chafing, melted insulation, or pinched wires.

2. 2

   Disconnect the sensor and check for water ingress, corrosion, or bent pins inside the connector.

3. 3

   Use a multimeter to verify the sensor's ground circuit. A broken or corroded ground wire will cause the sensor's signal voltage to float to the 5V reference maximum.

4. 4

   Check the signal wire to ensure it is not shorted to the 5V reference or 12V battery power.

5. 5

   If the 5V reference, ground, and signal wires all test good back to the ECU, verify if the sensor itself has failed internally.

1. 1

   Preparation

   Turn off the engine, remove the key, and disconnect the negative battery terminal.

2. 2

   Clean the Area

   Thoroughly clean the area around the fuel filter housing and the sensor to prevent dirt from entering the fuel system.

3. 3

   Relieve Pressure

   Place a rag under the sensor to catch any residual diesel fuel. The low-pressure side does not hold extreme pressure like the common rail, but some spillage will occur.

4. 4

   Remove the Sensor

   Unplug the electrical connector. Use a wrench to carefully unthread the faulty pressure sensor from the housing.

5. 5

   Install the New Sensor

   Thread the new OEM sensor into the housing. Tighten to the manufacturer's specified torque (do not overtighten, as the threads are often brass or fine-pitch).

6. 6

   Reassembly

   Reconnect the electrical harness, ensuring the locking tab clicks into place. Reconnect the battery.

7. 7

   Prime the System

   Turn the key to the "ON" position (without starting) to allow the electric lift pump to prime the low-pressure fuel system and bleed out any air. Check for leaks around the new sensor.

8. 8

   Clear Codes

   Use a diagnostic tool to clear the 000094.03 code from the ECU and start the tractor to verify the repair.