HOSE 2131724 - Caterpillar

Use this procedure in order to troubleshoot a problem with the fuel supply system or use this procedure if the following event code is active.
Table 1
Event Code
Code and Description Condition which Generated this Code System Response
E1128(1) High Fuel Filter (suction side) Intake Pressure The fuel supply pressure is above the programmed trip point for the programmed delay time. The code is logged. Probable Causes
Booster pump problem
Fuel pressure regulator problemRecommended Actions
Note: The procedures have been listed in order of probability. Complete the procedures in the order of the listed test steps.
Table 2
Troubleshooting Test Steps Values Results
1. Check for Codes
A. Connect Caterpillar Electronic Technician (ET) to the service tool connector. Refer to Troubleshooting, "Electronic Service Tools", if necessary.
B. Download the "Product Status Report" from the engine ECM before performing any troubleshooting or clearing diagnostic trouble codes.
C. Determine if the diagnostic trouble code that directed to this procedure is present.
D. Look for active diagnostic codes that are associated with the system for the event code that directed to this procedure.
E1128
Result: An associated code is present.
Repair: Troubleshoot any associated codes before continuing with this test.
Result: An E1128 code is present.
Proceed to the next step.
Result: No active codes
STOP
2. Check the Booster Pump
Note: The pump is a customer installed component.
A. Check the fuel pressure at the outlet of the booster pump.
B. If the outlet pressure of the booster pump is not within specifications, check for a problem with the booster pump.
Pressure
Result: The pressure is OK.
Proceed to the next step.
Result: The pressure is high and the booster pump is OK.
Proceed to the next step.
Result: The pressure is high and the booster pump is NOT OK.
Repair: Repair or replace the customer installed booster pump.
If the problem is not resolved, proceed the next step.
3. Check the Fuel Pressure Regulator
Note: The regulator is a customer installed component.
A. Check for a fuel pressure regulator between the booster pump at the fuel tank and the inlet of the primary fuel filters.
B. If a regulator is not installed in the fuel supply circuit between the booster pump and the inlet of the primary fuel filters, install a fuel pressure regulator in the circuit. Adjust the fuel pressure regulator in order to achieve the correct fuel pressure.
C. If a regulator is present, check the fuel pressure at the outlet of the regulator.
D. If the fuel pressure is not within specifications, adjust the regulator. If a problem with the regulator is suspected, replace the fuel pressure regulator.
Pressure
Result: No regulator.
Repair: Install a regulator and adjust the regulator.
Result: Regulator is present and pressure is high.
Repair: Adjust the regulator
Result: Regulator is present and suspected of failure.
Repair: Replace and adjust the regulator.