C175-20 Locomotive Engine Caterpillar

Use this procedure to troubleshoot high fuel pressure. Use this procedure if the following event code is active. Refer to Troubleshooting, "Codes" for information about event codes. For information on the engine monitoring system, refer to Troubleshooting, "Engine Monitoring System".

Table 1

J1939 Code and Description	CDL Code and Description	Comments
94-16 Engine Fuel Delivery Pressure : High - moderate severity (2)	E1218 (2) High Unfiltered Fuel Pressure	The fuel pressure before the secondary filter is higher than expected.

Table 2

Associated Diagnostic Trouble Codes
J1939 Code	CDL Code	Troubleshooting Procedure
95-0	E390 (3)	Troubleshooting, "Fuel Filter Is Restricted"
95-15	E390 (1)	Troubleshooting, "Fuel Filter Is Restricted"
95-16	E390 (2)	Troubleshooting, "Fuel Filter Is Restricted"

Table 3

Troubleshooting Test Steps	Values	Results
1. Check for Codes A. Apply electrical power to the engine. B. Connect Cat® Electronic Technician (ET) to the service tool connector. C. Look for active codes that are associated with the system for the event code.	Codes	Result: An associated code is active. Troubleshoot any associated codes before continuing with this test. Result: A code is active or logged. Proceed to Test Step 2.

Illustration 1	g03810811
Typical Fuel Filter (1) Starting priority valve (2) System pressure regulator

Table 4

Troubleshooting Test Steps	Values	Results
2. Check the Starting Priority Valve A. Remove electrical power from the engine. B. Remove the starting priority valve from the secondary fuel filter head. Refer to D&A manual for proper procedure. C. Check the starting priority valve operation by actuating the spool within the cartridge assembly.	Starting Priority Valve	Result: The starting priority valve moves freely through the full travel. Reinstall the starting priority valve. Proceed to Test Step 3. Result: The starting priority valve does NOT freely move through the full travel. Repair: Replace the starting priority valve. Proceed to Test Step 7.
3. Check the Low-Pressure Fuel System Pressure Regulator A. Remove electrical power from the engine. B. Remove the low-pressure fuel system pressure regulator from the secondary fuel filter auxiliary manifold. Refer to D&A manual for proper procedure. C. Check the low-pressure fuel system pressure regulator by actuating the spool within the cartridge assembly.	Low-Pressure Fuel System Pressure Regulator	Result: The low-pressure fuel system pressure regulator moves freely through the full travel. Reinstall the low-pressure fuel system pressure regulator. Proceed to Test Step 4. Result: The low-pressure fuel system pressure regulator does NOT freely move through the full travel. Repair: Replace the low-pressure fuel system pressure regulator. Proceed to Test Step 7.

Illustration 2	g03812528
Secondary Filter Assembly (14) Injector cooling orifice fitting

Table 5

Troubleshooting Test Steps	Values	Results
4. Check the Injector Cooling Supply Orifice A. Remove electrical power from the engine. B. Disconnect the injector cooling supply line from the secondary fuel filter head. C. Remove the orifice from the secondary fuel filter head. Refer to D&A manual for proper procedure. D. Inspect the injector cooling supply orifice.	Blockage	Result: The injector cooling supply orifice was NOT blocked. Reinstall the injector cooling supply orifice. Proceed to Test Step 5. Result: The injector cooling supply orifice was blocked. Repair: Clean the blockage from the injector cooling supply orifice. Proceed to Test Step 7.

Illustration 3	g03811112
Injector cooling back-pressure regulator (15) Pressure regulator

Table 6

Troubleshooting Test Steps	Values	Results
5. Check the Injector Backpressure Regulator A. Remove electrical power from the engine. B. Remove Injector backpressure regulator from the low-pressure injector cooling manifold in the fuel cooling rail. Refer to D&A manual for proper procedure. C. Check the Injector backpressure regulator by actuating the spool within the cartridge assembly.	Injector Backpressure Regulator.	Result: The Injector backpressure regulator moves freely through the full travel. Reinstall the Injector backpressure Regulator. Proceed to Test Step 6. Result: The Injector backpressure Regulator does NOT freely move through the full travel. Repair: Replace the Injector backpressure regulator. Proceed to Test Step 7.
6. Check the Fuel Cooler A. Remove electrical power from the engine. B. Install a pressure gauge in the inlet and outlet to the fuel cooler. C. Start the engine and operate at high idle.	Restriction	Result: The pressure drop across the fuel cooler was less than 10 kPa (1.5 psi). Proceed to Test Step 7. Result: The pressure drop across the fuel cooler was greater than 10 kPa (1.5 psi). A restricted fuel cooler has been detected. Repair: Replace the fuel cooler. Proceed to Test Step 7.
7. Check for Diagnostic Codes A. Start the engine and operate at high idle for 1 minute. B. Look for active or logged diagnostic codes.	Diagnostic Codes	Result: No codes present. Return to service.

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).