C175 Petroleum Engine Caterpillar

Use this procedure to troubleshoot abnormal fuel rail pressure or use this procedure if any of the following codes are active. Refer to Troubleshooting, "Diagnostic Trouble Codes" for information about the codes.

Table 1

J1939 Code and Description	CDL Code and Description	Comments
157-7 Engine Injector Metering Rail #1 Pressure : Not Responding Properly	E1069 (1) Fuel Rail #1 Pressure Not Responding	The engine fuel rail pressure sensor reading is unstable or incorrect.

Table 2

Associated Codes
J1939 Code	CDL Code	Troubleshooting Procedure
1076-7	18-7	The actual position and the desired position of the fuel actuator is not within specifications. Replace the fuel control valve.
1381-17	E2172 (1)	Troubleshooting, "Fuel Transfer Pump Inlet Pressure Is Low"

Probable Causes

• Codes

• Air in fuel

• Relief Valve

Recommended Actions

Show/hide table

Contact with high pressure fuel may cause fluid penetration and burn hazards. High pressure fuel spray may cause a fire hazard. Failure to follow these inspection, maintenance and service instructions may cause personal injury or death.

Table 3

Troubleshooting Test Steps	Values	Results
1. Diagnostic 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.	Diagnostic 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. Check for Air in the Fuel A. Refer to Testing and Adjusting, "Air in Fuel" for additional information.	Air in Fuel	Result: There was not air in the fuel. Proceed to Test Step 3. Result: There was air in the fuel. Repair: Determine the cause of the air in the fuel. Repair as necessary. If the problem is not resolved, proceed to Test Step 4.

Illustration 1	g06089463
High-Pressure Fuel Pump (1) Pump head (2) Valve block

Table 4

3. Check the Fuel Pressure Relief Valve A. Start the engine and allow the engine to run until operating temperature is reached. B. Run the engine at high idle. C. Use a 349-4203 Infrared Thermometer to measure the temperature difference between valve block (2) and pump head (1).	Temperature	Result: The temperature difference is less than 40° C (72° F). A failed fuel rail pressure sensor has been detected. Repair: Release the pressure in the high-pressure rail by loosening the end plug on one of the last two fuel accumulators. Refer to Testing and Adjusting, "Fuel Rail Pressure - Release" for instructions on how to release the pressurized fuel. Verify the "Fuel Rail Pressure" reading in ET is 0 ± 8 MPa (0 ± 1160 psi) prior to servicing the fuel system. Replace the fuel rail pressure sensor. Result: The temperature difference is more than 40° C (72° F). A failed high-pressure fuel pump has been detected. Repair: Replace the high-pressure fuel pump. If the problem is not resolved, proceed to Test Step 4.
4. Check for Codes A. Start the engine and allow the engine to run until operating temperature is reached. B. Look for active or logged codes.	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).