C7.1 Marine Engine Caterpillar

Fuel Rail Pressure Problem

Usage:

C7.1 JEZ

Use this procedure in order to troubleshoot abnormal fuel rail pressure or use this procedure if any of the following diagnostic trouble codes are active. Refer to Troubleshooting, "Diagnostic Trouble Codes" for information about the codes.

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Contact with high pressure fuel may cause fluid penetration and burn hazards. High pressure fuel spray may cause a fire hazard. Failure to follow these inspection, maintenance and service instructions may cause personal injury or death.

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NOTICE

Contact with high pressure fuel may cause personal injury or death. Wait 60 seconds after the engine has stopped to allow fuel pressure to purge before any service or repair is performed on the engine fuel lines.

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Table 1
Diagnostic Trouble Codes
J1939 Code	Code Description (code descriptions may vary)	Comments
157-16	Engine Injector Metering Rail #1 Pressure : High - moderate severity (2)	No codes for the high-pressure fuel pump or the injectors are active. The fuel rail pressure is above an acceptable level. The code is logged. Engine power is derated.
157-18	Engine Injector Metering Rail #1 Pressure : Low - moderate severity (2)	No codes for the high-pressure fuel pump or the injectors are active. The fuel rail pressure is below an acceptable level. The code is logged. Engine power is derated.

Probable Causes

Diagnostic codes
Electrical connectors
Fuel filters
Fuel rail pressure sensor
High-Pressure fuel pump calibration
Fuel system

Recommended Actions

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Table 2
Troubleshooting Test Steps	Values	Results
1. Diagnostic Codes A. Connect the electronic service tool to the diagnostic connector. Refer to Troubleshooting, "Electronic Service Tools", if necessary. B. Determine if a diagnostic is active or recently logged.	Diagnostic codes	Result: One of the diagnostic codes listed in Table 1 is active or recently logged. Proceed to Test Step 2. Result: A code other than those listed in Table 1 is present. Repair: Troubleshoot the code. Refer to the applicable troubleshooting procedure.
2. Electrical Connectors A. Check for the correct installation of the ECM J1/P1 and the J2/P2 connectors. Check for correct installation of the connector on the fuel rail pressure sensor.	Connectors	Result: There are suspect connectors. Repair: Use the electronic service tool to perform the "Wiggle Test". Repair or replace connectors that are suspect. Result: There are no suspect connectors. Proceed to Test Step 3.
3. Fuel Filters A. Replace the primary fuel filter and the secondary fuel filters. Refer to the Operation and Maintenance Manual for further information.	Fuel filters	Result: The filters have been replaced and the fault is eliminated. Return the unit to service. Result: The filters have been replaced and the fault is still present. Proceed to Test Step 3.
4. Fuel Rail Pressure Sensor A. Make sure that the engine has been shut down for at least 10 minutes. Use the electronic service tool to check the status of the "Fuel Rail Pressure"	Pressure sensor	Result: The "Fuel Rail Pressure (absolute)" is more than 5,000 kPa (725 psi). Repair: Test the fuel rail pressure sensor. Refer to Troubleshooting, "Sensor Signal (analog, Active) - Test". Use the electronic service tool in order to perform the "Fuel Rail Pressure Test". If the test fails, replace the fuel rail. Refer to Disassembly and Assembly, "Fuel Manifold (Rail) - Remove and Install". Confirm that the fault has been eliminated. Result: The "Fuel Rail Pressure (absolute)" is less than 5,000 kPa (725 psi). For a 157-16 code, proceed to Test Step 5. For a 157-18 code, proceed to Test Step 6.
5. High-Pressure Fuel Pump Calibration A. Use the electronic service tool to perform the "High Pressure Fuel Pump Calibration".	HP fuel pump	Result: The High-Pressure Fuel Pump Calibration was successful. Contact the Dealer Solutions Network (DSN). Result: The High-Pressure Fuel Pump Calibration was not successful. If the fuel rail pressure is high, contact the Dealer Solutions Network (DSN). If the fuel rail pressure is low, proceed to Test Step 6.
6. Fuel System A. Make sure that the level of fuel in the fuel tank is sufficient. B. Check the high-pressure fuel system for leaks. C. Check for air in the low-pressure fuel system. Refer to Systems Operation, Testing, and Adjusting, "Air in Fuel - Test".	Fuel system	Result: A fault was found in the fuel system. Repair: Rectify any faults and confirm that the fault is eliminated. Result: The fuel system is OK. Proceed to Test Step 7.
7. Pressure Limiting Valve (PLV) A. Use the electronic service tool in order to perform the "Fuel Rail Pressure Relief Valve Test". Note: This test will identify excessive leakage through the PLV in the fuel rail.	Pressure limiting valve	Result: The PLV has excessive leakage. Repair: Replace the fuel rail. Refer to Disassembly and Assembly, "Fuel Manifold (Rail) - Remove and Install". Verify that the repair eliminated the problem.

If the procedure did not correct the issue, contact your Cat dealer Technical Communicator (TC). For further assistance, your TC can confer with the Dealer Solutions Network (DSN).