Massey Ferguson 157.02 – Engine ECU: Fuel Rail Pressure Erratic

The Engine Control Unit (ECU) is receiving invalid, intermittent, or missing pressure information from the fuel rail pressure sensor, which typically forces the engine into a derated limp mode or causes it to run in an open-loop failure mode.

• 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
• 4600 series
• 5400 series
• 5700 series
• 6400 series
• 6600 series
• 6700 series
• 7400 series
• 7600 series
• 7700 series
• 8400 series
• 8600 series
• 8700 series

1. 1

   Inspect the 3-pin electrical connector at the fuel rail pressure sensor for corrosion, backed-out pins, or wire chafing.

2. 2

   Perform a voltage test on the sensor harness (ECU side). With ignition on and sensor unplugged, verify exactly 5 Vdc across Pin A24 (5 Vdc reference) and Pin A57 (ground). Pin A26 is the analog signal return.

3. 3

   Verify low-pressure fuel supply between the fuel filter and high-pressure pump inlet is at least 5 bar (72 psi) to rule out a starving high-pressure pump.

4. 4

   Check for vacuum restriction between the low-pressure pump inlet and fuel tank; ensure it does not exceed 127 mm (5 inches) of Hg to rule out a clogged filter or blocked line.

5. 5

   Inspect the main ECU connectors for water intrusion or corrosion, which can cause intermittent NO SIGNAL faults.

1. 1

   Depressurize

   Turn off the engine, remove the key, and wait at least 5–10 minutes for the high-pressure fuel rail to naturally depressurize.

2. 2

   Locate & Clean

   Locate the fuel rail pressure sensor threaded into the common fuel rail. Thoroughly clean the area around the sensor with brake cleaner and compressed air to prevent any dirt from entering the open fuel rail.

3. 3

   Disconnect

   Unplug the 3-pin electrical connector from the sensor.

4. 4

   Remove

   Using the appropriate wrench, carefully unscrew the faulty sensor from the rail.

5. 5

   Install

   Thread the new OEM fuel rail pressure sensor into the rail. Torque it strictly to the manufacturer's specification (over-tightening can damage the rail; under-tightening will cause high-pressure leaks).

6. 6

   Reconnect

   Plug the 3-pin connector back in, ensuring it clicks and locks securely.

7. 7

   Prime & Clear

   Turn the ignition to the ON position to allow the lift pump to prime the system. Use a diagnostic service tool to clear the 000157.02 fault code from the ECU.

8. 8

   Test

   Start the engine, check for any fuel leaks around the sensor threads, and verify that the erratic pressure code does not return.