BRACKET 4F1121 - Caterpillar

The Electronic Control Module (ECM) detects an abnormal fuel filter differential pressure.Use this procedure to troubleshoot a problem with the fuel filters. Also, use this procedure if one of the following event codes are active or logged.
Table 1
J1939 Code and Description CDL Code and Description Comments
95-0
Engine Fuel Filter Differential Pressure : High - most severe (3) E390 (3)
Fuel Filter Restriction The difference between the filtered fuel pressure and the unfiltered fuel pressure is greater than the trip point pressure.
The engine Electronic Control Module (ECM) will derate engine power.
The code is logged.
Change the fuel filter.
95-15
Engine Fuel Filter Differential Pressure : High - least severe (1) E390 (1)
Fuel Filter Restriction The difference between the filtered fuel pressure and the unfiltered fuel pressure is greater than the trip point pressure.
The engine ECM will derate engine power.
The code is logged.
Change the fuel filter.
95-16
Engine Fuel Filter Differential Pressure : High - moderate severity (2) E390 (2)
Fuel Filter Restriction The difference between the filtered fuel pressure and the unfiltered fuel pressure is greater than the trip point pressure.
The engine ECM will derate engine power.
The code is logged.
Change the fuel filter. Probable Causes
Fuel filterRecommended Action
Note: Change the primary filter, the secondary filter, and the tertiary filter at the same time. Use clean fuel on the stud threads of filter base to reduce friction.Note: Do not fill the canister or the fuel filter before installation. The fuel can carry debris into the fuel filter and the fuel system may be damaged. The electric priming pump is designed to purge the trapped air in the new filters.
Table 2
Troubleshooting Test Steps Values Results
1. Change the Fuel Filters
A. Reset all active codes and clear all logged codes by cycling the keyswitch to the Off position. Change the primary fuel filter.
B. Prime the system with the electric priming pump.
C. Start the engine and allow the engine to idle for few minutes.
D. Turn the engine OFF and change the secondary fuel filter.
E. Prime the system with the electric priming pump.
F. Start the engine and allow the engine to idle for few minutes.
G. Turn the engine OFF and change the tertiary fuel filter.
H. Prime the system with the electric priming pump.
J. Restart the engine.
Fuel Filter
Result: A code is not active or logged.
Return to service.
Result: The event code becomes active after changing the fuel filters.
Repair: The problem may be electrical. Refer to Troubleshooting, "Sensor Signal (Analog, Active) - Test" for additional information.
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).