Massey Ferguson E157.20 – Engine Control Unit (ECU): Fuel Rail Pressure Is Not As Expected During Startup Or Shutdown (ECU)

The engine control module has detected an anomaly in the common rail fuel pressure—it is either failing to build adequate pressure during engine cranking/startup, or it is not bleeding off pressure correctly during the shutdown sequence.

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

1. 1

   Check the low-pressure fuel system for adequate, uncontaminated fuel in the tank

2. 2

   Inspect the low-pressure lift pump and fuel lines for air leaks, blockages, or collapsed hoses that could starve the high-pressure pump

3. 3

   Inspect the primary and secondary fuel filters for clogging or water contamination

4. 4

   Inspect the wiring harness and the 3-pin connector at the Fuel Rail Pressure Sensor for corrosion, loose pins, or chafed wires

5. 5

   Test the mechanical pressure relief valve (PRV) on the fuel rail to ensure it is not stuck open or leaking fuel back into the return line prematurely

1. 1

   Depressurize the System

   Ensure the engine is off and the high-pressure fuel system has fully depressurized before opening any lines.

2. 2

   Service Fuel Filters

   If the filters are old or contaminated, replace them and bleed the low-pressure fuel system to ensure no air is trapped in the lines.

3. 3

   Replace the Fuel Rail Pressure Sensor

   If diagnostics point to a faulty sensor reading, disconnect the electrical harness, unscrew the old sensor from the fuel rail, and install the new OEM sensor. Torque to the manufacturer's exact specifications to prevent leaks or thread damage.

4. 4

   Address the PRV or High-Pressure Pump

   If the sensor and low-pressure system are functioning properly, the issue likely lies with a leaking fuel pressure relief valve or a failing high-pressure fuel pump/metering unit. Replace the faulty mechanical component.

5. 5

   Clear Codes and Test

   Use a diagnostic tool to clear the E157.20 code from the ECU. Perform several engine startup and shutdown cycles to verify that the rail pressure now meets the ECU's expected parameters.