C175 Oil&Gas Offshore Engine Caterpillar

Use this procedure in order to troubleshoot a high fuel leakage from the high-pressure fuel rail. Also, use this procedure if the following event code is active.

Table 1

	Event Codes
	CDL Codes and Description	Conditions which Generate this Code	System Response
1239–0 Engine Fuel Leakage 1 : High - Most Severe (3)	E499(3) Fuel Rail #1 Pressure Leak	The fuel leak detection sensor has detected fuel leakage in the high-pressure fuel system.	The code is logged.
1239–31 Fuel Rail #1 Pressure Leak : Condition Exists	E499(1) Fuel Rail #1 Pressure Leak

Probable Causes

• Diagnostic codes and event codes

• Leak detection sensor problem

• One-way check valve leak

• High-pressure fuel rail leak

Recommended Actions

Show/hide table

Fuel leaked or spilled onto hot surfaces or electrical components can cause a fire. Clean up fuel spills immediately.

Illustration 1	g02558636
Location of the components for leak detection (right side engine view) (1) Fuel leakage manifold (2) Fluid level sensor (3) One-way check valve (4) Outer wall fuel drain line (5) Plug

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.	E499	Result: An associated code is present. Repair: Troubleshoot any associated codes before continuing with this test. Result: An E499 code is present. Proceed to the next step. Result: No active codes STOP
2. Check the Leak Detection Sensor A. Determine if there is a leak to be detected . 1. Remove plug (5) from fuel leakage manifold (1). 2. Determine if fuel is present in the manifold.	Leak	Result: Fuel is found in the manifold. The sensor is OK. Proceed to Step 4. Result: Fuel is not found in the manifold. There is no leak to be detected. Proceed to the next step.
3. Check the Sensor Circuit Components A. Use Cat ET to monitor the following parameter: "High Pressure Fuel Line Status" B. Disconnect the sensor harness at the sensor (2). The status for the parameter will read "Leakage Detected". C. At the harness connector for the sensor, short the signal (terminal 2) to the ground (terminal 3) . The status for the parameter will read "No Leakage Detected".	Parameter status	Result: The parameter read as expected. The wiring and ECM have checked OK. Repair: Replace the sensor. Result: The parameter did not read as expected. There is a problem with the circuit for the sensor. Repair: Repair the circuit. Refer to Troubleshooting, "Switch Circuits - Test"
4. Check the High-pressure Fuel Rail for a Leak A. Remove drain line (4) from the manifold. B. Run the engine and observe the open drain line.	Leak	Result: Fuel is draining from the open drain line. There is a leak in the high-pressure fuel system. Repair: Determine the source of the leak. Refer to Testing and Adjusting, "Fuel Rail Leakage - Check" for the correct troubleshooting procedure.
5. Check the One-way Check Valve for a Leak B. Run the engine and observe the manifold port for fuel flow.	Leak	Result: Fuel is draining from the port for the plug (5). Repair: Replace the one-way check valve.

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).