PAN-OIL 7C1938 - Caterpillar

Use this procedure to troubleshoot a problem with low fuel pressure. Also, use this procedure if one of the following event codes is active or logged.
Table 1
J1939 Code and Description CDL Code and Description Comments
5580-18
Engine Filtered Fuel Delivery Absolute Pressure : Low - moderate severity (2) E198 (2)
Low Fuel Pressure The fuel pressure has dropped below trip point for the specified delay time.
The code is logged. Probable Causes
Codes
Fuel system
Sensor
Pressure Regulator
Transfer PumpRecommended Actions
Table 2
Troubleshooting Test Steps Values Results
1. Check for Codes
A. Connect Cat® Electronic Technician (ET) to the service tool connector.
B. Look for active codes that are associated with the system for the event code.
Codes
Result: An associated code is active.
Repair: Troubleshoot any associated codes before continuing with this test.
Result: A code is active or logged.
Proceed to Test Step 2.
2. Inspect the Fuel System
Refer to Testing and Adjusting, "Fuel System Inspection" for additional information.
A. Visually check the fuel level in the fuel tank. Do not rely on the fuel gauge only.
B. Ensure that the vent in the fuel cap is not filled with debris.
C. Ensure that the fuel supply valve (if equipped) is in the full OPEN position.
Note: Cold weather adversely affects the characteristics of the fuel. Refer to the engines Operation and Maintenance Manual for information on improving the characteristics of the fuel during cold-weather operation.
D. Check fuel quality. Refer to Testing and Adjusting, "Fuel Quality - Test" for additional information. Check the fuel tank for debris or foreign objects which may block the fuel supply.
E. Check for fuel leaks.
Fuel System
Result: The fuel system is OK.
Proceed to Test Step 3.
Result: The fuel system is NOT OK.
Repair: Repair or replace damaged fuel system components.
If the problem is not resolved, proceed to Test Step 3.
3. Check the Fuel Pressure Sensor
A. Start the engine. Run the engine at low idle.
B. Connect Cat ET.
C. Use Cat ET to monitor the following pressure:
- Fuel pressure
D. Increase the engine speed while you monitor the parameter. Ensure that the value of the parameter increases with engine speed. Ensure that the value of the sensor remains reasonable as the pressure is increased.
Sensor
Result: The value of the fuel pressure is reasonable.
Proceed to Test Step 4.
Result: The value of the fuel pressure is not reasonable.
Repair: Replace the pressure sensor.
If the problem is not resolved, proceed to Test Step 4.
4. Inspect the Pressure Regulator
A. Clean any contamination or debris that may keep the regulating valve open. Check the regulator for damage.
B. If the fuel pressure is not within specifications, adjust the regulator. Refer to System Operation Testing and Adjusting, "Fuel Pressure (Diesel System)". If a problem with the regulator is suspected, replace the fuel pressure regulator.
Pressure Regulator
Result: The pressure is within specifications.
Proceed to Test Step 5.
Result: The pressure is not within specifications.
Repair: Adjust or replace the pressure regulator.
If the problem is not resolved, proceed to Test Step 5.
5. Replace the Transfer Pump
A. Start the engine. If the fuel pressure decreases after starting the engine, replace the fuel transfer pump.
Transfer Pump
Result: The transfer pump was replaced.
Verify that the repair eliminated the