C7.1 Engines For Caterpillar Built Machines Caterpillar

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

Table 1

Diagnostic Trouble Codes
CDL Code	Code Description	Comments
E396-2	High Fuel Rail Pressure : moderate severity (2)	No 1797-XX codes are active. 262-XX codes are not active. 2131-XX codes are not active. No codes for the high-pressure fuel pump or the injectors are active. The fuel rail pressure is above an acceptable level. The code is logged. Engine power is derated.
E398-2	Low Fuel Rail Pressure : moderate severity (2)	No 1797-XX codes are active. 262-XX codes are not active. 2131-XX codes are not active. No codes for the high-pressure fuel pump or the injectors are active. The fuel rail pressure is below an acceptable level. The code is logged. Engine power is derated.
E499-3	Fuel Rail #1 Pressure Leak : most severe (3)	262-XX codes are not active. 2131-XX codes are not active. There is a probable fuel leak from the high-pressure fuel system. The amount of leakage is a calculated parameter. The code is logged. The engine will shut down.
E1264-2	High Pressure Common Rail Fuel Pressure Relief Valve Active : moderate severity (2)	262-XX codes are not active. 2131-XX codes are not active. The pressure limiting valve in the fuel rail is open. This code is a calculated parameter. The code is logged.

Probable Causes

• Diagnostic trouble codes

• Electrical connectors

• Fuel filters

• Fuel rail pressure sensor

• Fuel system

Recommended Actions

Diagnostic Trouble Codes

Use one of the following methods to check for active diagnostic trouble codes:

• The electronic service tool

• The display on the control panel

Electronic Service Tool

1. Connect the electronic service tool to the diagnostic connector.

2. Check for active diagnostic trouble codes on the electronic service tool.

3. Investigate any active codes before continuing with this procedure. Refer to Troubleshooting, "Troubleshooting with a Diagnostic Code".

Display on the Control Panel

Note: The following procedure is only applicable if the application is equipped with a display on the control panel.

1. Check the display on the control panel for active diagnostic trouble codes.

2. Troubleshoot any active codes before continuing with this procedure. Refer to Troubleshooting, "Diagnostic Trouble Codes".

Electrical Connections

1. Check for correct installation of the P1 and P2 connectors on the ECM. Check for correct installation of all other applicable connectors. Refer to Troubleshooting, "Electrical Connectors - Inspect".

2. Use the electronic service tool to perform a wiggle test.

3. If necessary, perform any repairs to the connectors or the wiring.

4. Check if the fault has been eliminated. If the fault is still present, proceed to "Fuel Filters".

Fuel Filters

1. Replace the in-line fuel strainer that is installed upstream of the Electric Fuel Lift Pump (EFLP).

2. Replace the primary fuel filter and the secondary fuel filter. Refer to the applicable procedure in the Operation and Maintenance Manual.

3. Check if the fault has been eliminated. If the fault is still present, proceed to "Fuel Rail Pressure Sensor".

Fuel Rail Pressure Sensor

1. With the engine shutdown, use the electronic service tool to check the status of the "Fuel Rail Pressure". After the engine has been shut down for 10 minutes, the "Fuel Rail Pressure (absolute)" must be less than 5,000 kPa (725 psi) (gauge).

2. If the "Fuel Rail Pressure" on the electronic service tool is less than 5,000 kPa (725 psi), proceed to Step 4.

3. If the "Fuel Rail Pressure" on the electronic service tool does not fall to less than 5,000 kPa (725 psi) (gauge), the fuel rail pressure sensor may be faulty. Refer to Troubleshooting, "Engine Pressure Sensor Open or Short Circuit - Test".

4. Use the electronic service tool in order to perform the "Fuel Rail Pressure Test". If the test fails, replace the fuel rail. Refer to Disassembly and Assembly, "Fuel Manifold (Rail) - Remove and Install".

5. If the fault is still present, proceed to "Fuel System".

Fuel System

High Fuel Rail Pressure

1. Use the electronic service tool in order to perform the Fuel Rail Pressure Test. If the test fails, replace the SCV and solenoid. Refer to Disassembly and Assembly, "Fuel Pump Solenoid - Remove and Install".

2. If a fault is not identified for the SCV, use the electronic service tool to perform the "High Pressure Fuel Pump Calibration".

3. If the fuel rail pressure is still high, perform the following procedure:

   Note: Before performing the following fuel system tests, the engine must be stopped for a minimum of 30 minutes.

   Note: When performing the following fuel system tests, the Electric Fuel Lift Pump (EFLP) will only operate for 2 minutes unless the engine is running. If necessary, cycle the keyswitch in order to reactivate the pump.

Illustration 1	g02460136
(1) Transfer pump inlet regulator (TPIR) (2) Transfer pump inlet regulator return port

Transfer Pump Inlet Regulator (TPIR) Flow Test

Refer to Illustration 1.

1. Disconnect the TPIR return line from the drain port on the TPIR. Install a suitable blanking cap on the open port in the TPIR return line

2. Connect a temporary drain line to the drain port on the TPIR.

3. Place the end of the temporary drain line into a suitable calibrated container.

4. With the keyswitch in the ON position but the engine not running, use a suitable multimeter to measure the input voltage to the EFLP. Record the reading.

5. With the keyswitch in the ON position but the engine not running, measure the fuel flow from the temporary drain line. Refer to Illustration 2 for the minimum acceptable flow rate.

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Illustration 2	g02355130
Minimum TPIR flow rate

6. Remove the temporary drain line from the drain port on the TPIR. Connect the TPIR return line to the TPIR.

7. If the fuel flow in Step 5 is greater than the minimum limit, contact the technical communicator at a Caterpillar dealer.

8. If the fuel flow in Step 5 is below the minimum limit or there is no fuel flow, replace the EFLP.

Transfer Pump Inlet Regulator (TPIR) Return Test

In order to check the return flow from the TPIR, perform the following procedure:

1. Make sure that the TPIR return line is not blocked or kinked.

2. If the TPIR return line is clear, confirm that the Electric Fuel Lift Pump (EFLP) is operating. Make sure that the fuel lines between the EFLP and the TPIR are not blocked or kinked.

3. If the fuel lines to the TPIR are clear and the EFLP is operating, replace the TPIR.

4. If the fault is still present, contact the technical communicator at a Caterpillar dealer.

Low Fuel Rail Pressure

1. Make sure that the level of fuel in the fuel tank is sufficient. If necessary, fill the fuel tank.

2. Inspect the high-pressure fuel system for leaks. Rectify any fuel leaks.

3. Use the electronic service tool to perform the "High Pressure Fuel Pump Calibration".

4. Check that the Electric Fuel Lift Pump (EFLP) is operating. If the EFLP is suspect, refer to Troubleshooting, "Fuel Pump Relay Circuit - Test".

5. Check for the introduction of air in the low-pressure fuel system. Refer to Systems Operation, Testing, and Adjusting, "Air in Fuel - Test". If necessary, rectify the cause of air in the fuel.

6. Use the electronic service tool in order to perform the "Fuel Rail Pressure Relief Valve Test". This test will identify excessive leakage through the Pressure Limiting Valve (PLV) in the fuel rail. If excessive leakage is identified, replace the fuel rail. Refer to Disassembly and Assembly, "Fuel Manifold (Rail) - Remove and Install".

7. Turn the keyswitch to the OFF position and then disconnect the electrical connector from the EFLP.

8. With the keyswitch in the ON position, measure the voltage at the harness connector for the EFLP. The voltage must be between 20 VDC and 28 VDC. If the voltage is below 20 VDC, investigate the cause.

9. Turn the keyswitch to the OFF position and then reconnect the electrical connector to the EFLP.

10. If a repair has been performed to rectify a low supply voltage to the EFLP, attempt to start the engine. If the engine does not start, continue with this procedure.

    Note: Before performing the following fuel system tests, the engine must be stopped for a minimum of 30 minutes.

    Note: When performing the following fuel system tests, the Electric Fuel Lift Pump (EFLP) will only operate for 2 minutes unless the engine is running. If necessary, cycle the keyswitch in order to reactivate the pump.

11. Use the following procedure to check the flow from the Transfer Pump Inlet Regulator (TPIR):
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    Illustration 3	g02522678
    Locations in the low-pressure fuel system (1) Fuel return line to the secondary fuel filter (2) Secondary fuel filter base (3) Transfer Pump Inlet Regulator (TPIR) (4) TPIR return port

    1. Disconnect the TPIR return line from the drain port (4) on the TPIR (3). Install a suitable blanking cap on the open port in the TPIR return line

    2. Connect a temporary drain line to the drain port on the TPIR.

    3. Place the end of the temporary drain line into a suitable calibrated container.

    4. With the keyswitch in the ON position but the engine not running, use a suitable multimeter to measure the input voltage to the EFLP. Record the reading.

    5. With the keyswitch in the ON position but the engine not running, measure the fuel flow from the temporary drain line. Refer to Illustration 4 for the minimum acceptable flow rate.
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    Illustration 4	g02522799
    Minimum TPIR flow rate

    6. Remove the temporary drain line from the drain port on the TPIR. Connect the TPIR return line to the TPIR.

    7. If the fuel flow in Step 11.e is greater than the minimum limit, contact the technical communicator at a Caterpillar dealer.

    8. If the fuel flow in Step 11.e is below the minimum limit, continue with this procedure.

12. Use the following procedure to check the fuel flow through the return pressure relief valve in the secondary fuel filter base:

    1. Disconnect the return line (1) from the secondary fuel filter base and install a blank on the line. Install a temporary line and a calibrated container to the filter base.

    2. With the keyswitch in the ON position, measure fuel flow from the temporary line.

    3. If the fuel flow is more than 300 mL/min (10.2 oz/min), replace the secondary fuel filter base. Refer to Disassembly and Assembly, "Fuel Filter Base - Remove and Install (Twin Secondary Fuel Filter)".

    4. Remove the temporary line and reconnect the return line.

13. If the secondary fuel filter base has been replaced, attempt to start the engine. If the engine does not start, use the following procedure to check the fuel flow from the EFLP:

    1. Disconnect the fuel inlet from the primary fuel filter. Place the open end of the disconnected line into a calibrated container.

    2. With the keyswitch in the ON position, measure the flow from the fuel line. Refer to Illustration 5 for the minimum acceptable fuel flow.
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    Illustration 5	g02523082
    Minimum EFLP flow rate

    3. If the fuel flow is more than 5% below the acceptable limit, replace the EFLP.

    4. If the fuel flow is more than 5% above the acceptable limit, contact the Technical Communicator at a Caterpillar dealer.

14. If the fuel flow from the EFLP is within limits, perform the following procedure:

    1. Make sure that the TPIR return line is not blocked or kinked.

    2. If the TPIR return line is clear, confirm that the Electric Fuel Lift Pump (EFLP) is operating. Make sure that fuel lines between the EFLP and the TPIR are not blocked or kinked.

    3. If the fuel lines to the TPIR are clear and the EFLP is operating, replace the TPIR.

15. If the fault is still present, contact the technical communicator at a Cat dealer.