COUPLER GP-QUICK 4855224 - Caterpillar

Use this procedure to troubleshoot abnormal fuel rail pressure.Probable Causes
Diagnostic trouble codes
Electrical connectors
Fuel filters
Fuel rail pressure sensor
Fuel system inspection
Fuel rail Pressure Relief Valve (PRV)
High-pressure fuel pumpRecommended Actions
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. Use the electronic service tool to check for active diagnostic codes.
Diagnostic codes
Result: One of the diagnostic codes listed in Table 1 is active.
Proceed to Test Step 2.
Result: A diagnostic code that is not listed in Table 1 is active.
Repair: Troubleshoot the code. Refer to Troubleshooting, "Diagnostic Trouble Codes".
Result: There are no active diagnostic codes.
Return the engine to service.
2. Battery Supply
A.Check the battery supply voltage to the engine ECM.
B. If the application is equipped with a voltage converter, ensure that the voltage converter is operating correctly.
Note: A voltage converter is required if the application has a 24V system. The engine ECM requires 12V.
Battery supply
Result: The battery supply voltage is OK.
Proceed to Test Step 3.
Result: The battery supply voltage is not OK.
Repair: Make any necessary repairs.
3. 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: Repair or replace connectors that are suspect.
Result: There are no suspect connectors.
Proceed to Test Step 4.
4. 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 5.
5. 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: Replace the fuel rail pressure sensor. 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).
Proceed to Test Step 6.
6. Fuel System Inspection
A. Check that the fuel shut-off valve is in the OPEN position.
B. If the temperature is below 0 °C (32 °F), check for solidified fuel (wax).
C. Check for fuel supply lines that are restricted.
D. Check that the low-pressure fuel lines are correctly installed.
E. Check the pressures in the fuel system. Refer to Systems Operation, Testing, and Adjusting, "Fuel System Pressure - Test"
F. Check the diesel fuel for contamination. Refer to Systems Operation, Testing, and Adjusting, "Fuel Quality - Test".
G. Check for air in the fuel system. Refer to Systems Operation, Testing, and Adjusting, "Air in Fuel - Test".
H. Ensure that the fuel system has been primed. Refer to Systems Operation, Testing, and Adjusting, "Fuel System - Prime".
Fuel System
Result: A defect was found in the fuel system.
Repair: Make any necessary repairs.
Result: No defects found.
Proceed to Test Step