C6.6 Marine Generator Set Caterpillar

Probable Causes

• Diagnostic codes

• Electrical connectors

• ECM connection

• Fuel supply

• Intake manifold pressure

Recommended Actions

Diagnostic Codes

Check for active diagnostic codes on the electronic service tool. Troubleshoot any active codes before continuing with this procedure.

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 connected.

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

3. Verify the correct pin positions for the power connections and the ground connections for the Electronic Control Module (ECM).

4. If a fault is suspected with the ECM power and ground connections refer to Systems Operation, Testing and Adjusting, "Charging System - Test".

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

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

7. 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 the fuel filters.

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

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

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

11. Check the fuel pressure. Refer to Systems Operation, Testing and Adjusting, "Fuel System Pressure - Test".

12. If the repair does not eliminate the fault refer 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. Check the intake manifold pressure. The pressure should read 0 kPa (0 Psi).

4. Use the electronic service tool to check for the following logged diagnostic codes:
   • 1785-3 Intake Manifold Pressure Voltage High

   • 1785-4 Intake Manifold Pressure Voltage Low

   If either of these diagnostic codes are logged, proceed to Troubleshooting, "Engine Pressure Sensor Open or Short Circuit - Test".