Massey Ferguson 1381.18 – ECU: Fuel Pressure At The Inlet Of The High Pressure Pump Signal Voltage Issue (ECU)

This code indicates that the engine computer is receiving an abnormal or out-of-range voltage signal from the fuel pressure sensor located on the low-pressure side (at the inlet of the high-pressure injection pump). This can be caused by an actual low fuel pressure condition (such as a restriction), a faulty sensor, or an electrical wiring issue.

• 4710
• 7724S
• 5712SL
• 7722S
• 7722
• 5713SL
• 7720S
• 7716
• 7718
• T4
• 7715
• 5710SL
• 7726
• 4708
• 7726S
• 4707
• 4709
• 5711SL
• 7718S
• 7719
• 7714
• 7716S
• T4 (2015-2021)
• 7720
• Tier 4 (2015-2021)
• 7715S
• 7724
• 5608-5613
• 5710SL-5713SL
• 7614-7626
• 7714-7726S

1. 1

   Check Fuel Filters: A clogged primary fuel filter or water separator will restrict flow to the high-pressure pump inlet, causing an actual low-pressure reading. Inspect and replace filters if they are due for service.

2. 2

   Inspect the Wiring and Connector: Check the electrical connector at the fuel pressure sensor for corrosion, backed-out pins, or moisture. Inspect the wiring harness leading back to the ECU for chafing or shorts.

3. 3

   Verify Lift Pump Operation: Ensure the low-pressure lift pump is adequately supplying fuel to the high-pressure pump inlet.

4. 4

   Test Sensor Voltage: Use a multimeter to check the signal voltage coming from the sensor to see if it matches the ECU's expected parameters.

1. 1

   Relieve Pressure

   Relieve the fuel system pressure following your service manual's safety procedures. Even on the low-pressure side, diesel fuel can be under pressure.

2. 2

   Disconnect

   Unplug the electrical connector from the fuel pressure sensor.

3. 3

   Remove

   Unscrew the faulty sensor from its mounting point at the fuel pump inlet/rail.

4. 4

   Install

   Thread in the new sensor (note that these are typically M18x1.5 or M14x1.5 threads depending on the exact engine model). Tighten to OEM torque specifications.

5. 5

   Reconnect

   Plug the electrical connector back in.

6. 6

   Prime and Test

   Prime the fuel system to remove air, start the engine, and check for leaks.

7. 7

   Clear Codes

   Use a diagnostic scan tool to clear the 001381.18 code from the ECU. The system may require a brief relearn period.