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

Base code E94 indicates an issue with the fuel filter pressure, often triggered by low fuel pressure caused by restricted fuel flow. The .03 extension indicates the control module is receiving a voltage signal from the fuel filter pressure sensor that is higher than the normal operating range. This can be caused by a faulty sensor, a wiring issue (such as a short to power), or severe fuel flow restrictions like gelled fuel or heavily plugged filters.

• 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.