C7.1 Industrial Engine and Generator Set Caterpillar

Probable Causes

• Diagnostic codes

• Electrical connectors

• ECM connection

• Fuel supply

• Intake manifold pressure

Recommended Actions

Diagnostic Codes

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

• The electronic service tool

• The display on the control panel

• Flash Codes

Electronic Service Tool

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

2. Check for active diagnostic 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 codes.

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

Flash Codes

Note: The following procedure is only applicable if the machine is equipped with the appropriate warning lamps.

1. Check the warning lamps on the control panel for flash codes. Flash codes are explained in Troubleshooting, "Flash Codes".

2. If any flash codes are displayed, troubleshoot the codes before continuing with this procedure. Refer to Troubleshooting, "Troubleshooting with a Diagnostic Code".

Electrical Connectors

1. Refer to Troubleshooting, "Electrical Connectors - Inspect".

2. Repair the electrical connectors or replace the electrical connectors.

3. Ensure that all the connector seals are in place and that the connectors have been correctly installed.

4. Ensure that the repairs have eliminated the fault. If the fault has not been eliminated proceed to "ECM Connection".

ECM Connection

1. Check that the P2/J2 connector is correctly fitted.

2. Check that the P1/J1 connector is correctly fitted.

3. If a fault is suspected with the ECM power and ground connections, refer to Troubleshooting, "Ignition Keyswitch Circuit and Battery Supply Circuit - Test".

4. Verify that the ECM connections for the power and ground connections at the fuel pump are correctly connected.

5. Repair any faults and ensure that the faults have been eliminated.

6. If the repairs do not eliminate the faults, proceed to "Fuel Supply".

Fuel Supply

1. Visually check the fuel tank for fuel. The fuel gauge may be faulty.

2. Ensure that the fuel supply valve (if equipped) is in the full OPEN position.

3. If the temperature is below 0 °C (32 °F), check for solidified fuel (wax).

4. Check the primary filter/water separator for water in the fuel.

5. Check for fuel supply lines that are restricted.

6. Check that the low-pressure fuel lines are tight and secured properly.

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

8. Replace the in-line fuel strainer that is upstream of the primary fuel filter.

9. Replace the primary and secondary fuel filters.

10. Check the diesel fuel for contamination. Refer to Systems Operation, Testing, and Adjusting, "Fuel Quality - Test".

11. Check for air in the fuel system. Refer to Systems Operation, Testing, and Adjusting, "Air in Fuel - Test".

12. Ensure that the fuel system has been primed. Refer to Systems Operation, Testing, and Adjusting, "Fuel System - Prime".

13. Check the fuel pressure. Start the engine and then use the electronic service tool to check that the pressure in the fuel rail is more than 18000 kPa (2610 psi).

14. If the fault has not been eliminated, perform the following procedure:

    Note: Before performing the following fuel system tests, the engine must be run 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	g02873776
(1) Return line pressure relief valve (2) Secondary fuel filter base (3) Transfer pump inlet regulator (TPIR) (4) Transfer pump inlet regulator return port

Transfer Pump Inlet Regulator (TPIR) Flow Test

Refer to Illustration 1.

Perform the following procedure:

1. Make sure the keyswitch is in the OFF position.

2. 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

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

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

5. 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.

6. With the keyswitch in the ON position but the engine not running, measure the fuel flow from the temporary drain line. For a 12 VDC system, refer to Illustration 2 for the minimum acceptable flow rate. For a 24 VDC system, refer to Illustration 3 for the minimum acceptable flow rate.
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   Illustration 2	g02355128
   Minimum TPIR flow rate for a 12 VDC system

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   Illustration 3	g02355130
   Minimum TPIR flow rate for a 24 VDC system

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

8. If the fuel flow in Step 6 is greater than the minimum limit, proceed to "Intake Manifold Pressure".

9. If the fuel flow in Step 6 is below the minimum limit, proceed to "Return Line Pressure Relief Valve Test".

10. If there is no fuel flow in Step 6, proceed to "Transfer Pump Inlet Regulator (TPIR) Return Test".

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 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, proceed to "Intake Manifold Pressure".

Return Line Pressure Relief Valve Test

In order to check the return line pressure relief valve in the secondary fuel filter base, perform the following procedure:

1. Make sure the keyswitch is in the OFF position.

2. Disconnect the return line banjo connection on the top of the secondary fuel filter.

3. Use a suitable blank to plug the return line.

4. Install a suitable drain line to the return line point on the top of the secondary fuel filter.

5. Place the open end of the drain line in a suitable calibrated container.

6. With the keyswitch in the ON position, measure the flow from the drain line.

7. If the flow from the drain line is less than 0.4 L (24.4 cubic inch) per minute, proceed to "EFLP Flow Test at the Primary Fuel Filter Inlet".

8. If the flow from the drain line is more than 0.4 L (24.4 cubic inch) per minute, replace the secondary fuel filter head. Refer to Disassembly and Assembly, "Fuel Filter Base - Remove and Install".

EFLP Flow Test at the Primary Fuel Filter Inlet

In order to check the fuel flow from the EFLP at the primary fuel filter inlet, perform the following procedure:

1. Make sure the keyswitch is in the OFF position.

2. Disconnect the fuel inlet connection from the primary fuel filter head.

3. Install a suitable blank on the fuel inlet port on the primary fuel filter head.

4. Place the open end of the fuel inlet line in a suitable calibrated container.

5. With the keyswitch in the ON position, measure the input voltage at the EFLP. Record the result.

6. With the keyswitch in the ON position, measure the flow from the fuel inlet line. Record the result.

7. Check the recorded voltage and fuel flow on the graph in Illustration 4
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   Illustration 4	g02527498
   Minimum EFLP flow rate for a 12 VDC system

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   Illustration 5	g02527518
   Minimum EFLP flow rate for a 24 VDC system

8. If the fuel flow is below the minimum value for the recorded voltage, replace the EFLP. Refer to Disassembly and Assembly, "Fuel Priming Pump - Remove and Install ".

9. If the fuel flow is above the minimum value for the recorded voltage, proceed to "Check the Return Fuel Lines".

Check the Return Fuel Lines

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

2. 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.

4. If the fault is still present, proceed to "Intake Manifold Pressure".

Intake Manifold Pressure

1. Use the electronic service tool to verify the intake manifold pressure.

2. Turn the start switch to the ON position.

3. The intake manifold pressure should read 0 ± 0.5 kPa (0 ± 0.07 psi). If the intake manifold pressure is not within the limits, perform the following steps.

4. Check the air filter restriction indicator, if equipped.

5. Ensure that the air filter is clean and serviceable.

6. Check the air intake and the exhaust system for the following defects:

   • Blockages

   • Restrictions

   • Damage to the air intake and exhaust lines and hoses

7. If the fault cannot be eliminated, contact the technical communicator at a Caterpillar dealer.