John Deere 157.18 – ECU: Moderately Low Fuel Rail Pressure Detected

This code is triggered when the actual fuel rail pressure is slightly below the target level requested by the controller. It indicates a potential issue with fuel delivery, pressure regulation, or a leak in the system. The engine may exhibit reduced power output and efficiency as the system attempts to compensate for the lower-than-expected fuel pressure.

• 5085E
• 5090E
• 5090EL
• 5100E
• 5065M
• 5075M
• 5085M
• 5100M
• 5100MH
• 5100ML
• 5115ML
• 5090M
• 5115M
• 6110M
• 6120M
• 6130M
• 6145M
• 6155M
• 6175M
• 6195M
• 6110R
• 6120R
• 6130R
• 6145R
• 6155R
• 6175R
• 6195R
• 6215R
• 8530
• 9230
• 9330
• 9430
• 9530
• 9630
• 9370R
• 9420R
• 9470R
• 9520R
• 9570R
• 9620R
• 9470RT
• 9520RT
• 9570RT
• 9620RX

1. 1

   Inspect the low-pressure fuel system closely for any blockages, restrictions, or leaks that might be contributing to pressure loss.

2. 2

   Evaluate the low-pressure fuel transfer pump to ensure it is operating correctly and supplying adequate fuel to the high-pressure system.

3. 3

   Check the operation of the high-pressure fuel pump and the pressure regulator/relief valve to ensure they are functioning properly.

4. 4

   Test for excessive fuel return rates from the high-pressure fuel pump or the fuel injectors using diagnostic equipment to measure fuel pressure precisely.

1. 1

   Change fuel filters

   Replace the primary, secondary, and water separator fuel filters. This is the first and most common repair step dictated by John Deere ECU diagnostic manuals for this code.

2. 2

   Re-test the system

   After replacing the filters, run the engine to see if the ECU Engine System problem continues.

3. 3

   Repair or replace faulty components

   If the code returns after filter replacement, address the issues found during the diagnostic checks. This typically involves replacing a failing high-pressure fuel pump, a faulty fuel rail pressure relief valve, or leaking fuel injectors.

4. 4

   Reset the ECU

   After making the necessary repairs, reset the ECU and clear the error codes to ensure it accurately monitors and regulates fuel pressure going forward.