John Deere 157.1 – ECU (Engine Control Unit): Fuel Rail Pressure Loss Detected / Fuel Rail Pressure Dropping Too Fast

This code is triggered when the Engine Control Unit detects a sudden decrease in fuel rail pressure at times when the engine is neither injecting nor pumping fuel (e.g., when the engine is motoring and the high-pressure pump is off, the rail pressure decays too fast). This unusual drop indicates a high-pressure leak within the fuel system, faulty fuel pump operation, or an issue with the pressure relief valve. The ECU may adjust engine parameters to compensate, potentially leading to reduced performance, engine derating, or stalling.

• 6110M
• 6120M
• 6130M
• 6145M
• 6155M
• 6175M
• 6195M
• 6110R
• 6120R
• 6130R
• 6145R
• 6155R
• 6175R
• 6195R
• 6215R
• 5085M
• 5095M
• 5095MH
• 5105M
• 5015ML
• 6M Series (6105M–6170M)
• 6R Series (6110R–6215R)
• 6230
• 6330
• 6430 Premium
• 7R Series
• 8R/8RT Series
• 9230
• 9330
• 9430
• 9530
• 9630
• 6145J–6205J
• 7810
• 9540–9680 WTS/STS/CTS series
• 9670
• 3520 Sugar Cane Harvester
• 310J–710K Backhoe Loaders
• 130G Excavators
• 1070D–1470D Harvesters
• 4930 Self-Propelled Sprayer

1. 1

   Check all high-pressure fuel lines, connections, and fuel system components for any visible signs of fuel leakage.

2. 2

   Ensure fuel filters are not clogged or leaking (a leaking low-pressure fuel filter canister can sometimes contribute to pressure loss symptoms).

3. 3

   Test the functionality of the fuel rail pressure relief valve to ensure it is not bypassing fuel prematurely or failing to hold pressure.

4. 4

   Test the high-pressure fuel pump operation to ensure it is operating within specifications.

5. 5

   Use John Deere Service ADVISOR (or equivalent diagnostic equipment) to monitor real-time fuel rail pressure fluctuations and verify the rate of pressure drop when the engine is shut off or motoring.

1. 1

   Address Leaks

   Repair or replace any leaking fuel lines, fittings, or filter housings identified during the visual inspection.

2. 2

   Replace Faulty Components

   If the diagnostic tests point to a failure in maintaining pressure, replace the faulty component. This is most commonly the Fuel Rail Pressure Relief Valve, the Fuel Rail Pressure Sensor (if providing erratic/false readings), or the High-Pressure Fuel Pump.

3. 3

   Prime the System

   After opening the fuel system to replace parts, thoroughly bleed and prime the fuel system to remove all air.

4. 4

   Reset and Clear

   Reconnect diagnostic equipment, reset the ECU, and clear the fault codes to ensure the module correctly reads the restored fuel pressure levels.

5. 5

   Test Run

   Run the machine under load to verify that the fuel rail pressure remains stable and the 000157.10 code does not return.