C3.4B Engines Caterpillar

Power Is Intermittently Low or Power Cutout Is Intermittent

Usage:

CCS7 4B2

Note: Use this procedure only if the engine does not shut down completely.

Probable Causes

Diagnostic codes
Electrical connectors
ECM connection
Fuel system inspection
Air inlet and exhaust system

Recommended Actions

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NOTICE

Do not crank the engine continuously for more than 30 seconds. Allow the starting motor to cool for two minutes before cranking the engine again.

Note: The procedures have been listed in order of probability. Complete the procedures in order.

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Table 1
Troubleshooting Test Steps	Values	Results
1. Diagnostic Codes A. Establish communication between the electronic service tool and the Electronic Control Module (ECM). Refer to Troubleshooting, "Electronic Service Tools", if necessary. B. Use the electronic service tool to check for active diagnostic codes.	Diagnostic codes	Result: There are active or logged codes. Repair: Troubleshoot any codes before continuing with this procedure. Refer to Troubleshooting, "Diagnostic Trouble Codes". Result: There are no active or logged codes. Proceed to Test Step 2.
2. Electrical Connectors A. Check all electrical connectors for damage. Refer to Troubleshooting, "Electrical Connectors - Inspect". B. Make sure that all the connector seals are in place and that the connectors have been correctly installed.	Electrical connectors	Result: An electrical connector is damaged. Repair: Repair the electrical connector or replace the electrical connector. Result: A connector seal is displaced or missing or an electrical connector is not correctly installed. Repair: Repair the electrical connector or replace the electrical connector. Result: All electrical connectors are OK. Proceed to Test Step 3.
3. ECM Connection A. Check that the P2/J2 and P1/J1 connectors are correctly installed. Note: If a fault is suspected with the ECM power or ground connections, refer to Troubleshooting, "Electrical Power Supply - Test".	ECM connection	Result: An ECM connector is not correctly installed. Repair: Repair the electrical connector or replace the electrical connector. Result: Both ECM connectors are correctly installed. Proceed to Test Step 4.
4. Fuel System Inspection A. Check that the fuel shut-off valve is in the OPEN position. B. If the temperature is below 0 °C (32 °F), check for solidified fuel (wax). C. Check for fuel supply lines that are restricted. D. Check that the low-pressure fuel lines are correctly installed. E. Check the pressures in the fuel system. Refer to Systems Operation, Testing, and Adjusting, "Fuel System Pressure - Test" F. Check the diesel fuel for contamination. Refer to Systems Operation, Testing, and Adjusting, "Fuel Quality - Test". G. Check for air in the fuel system. Refer to Systems Operation, Testing, and Adjusting, "Air in Fuel - Test". H. Ensure that the fuel system has been primed. Refer to Systems Operation, Testing, and Adjusting, "Fuel System - Prime".	Fuel System	Result: A defect was found in the fuel system. Repair: Make any necessary repairs. Result: No defects found. Proceed to Test Step 5.
5. Fuel Filters A. Replace the primary fuel filter and the secondary fuel filter. Refer to the Operation and Maintenance Manual, "Fuel System Primary Filter (Water Separator) Element - Replace". B. Run the engine in the conditions that the fault occurred.	Fault cleared	Result: The fault has been rectified. Return the engine to service. Result: The fault is still present. Proceed to Test Step 6.
6. Air Inlet and Exhaust System A. Check the air filter restriction indicator. B. Ensure that the air filter is clean and serviceable C. Check the air intake and exhaust systems for the following defects: · Blockages · Restrictions · Damage to lines or hoses	Defects	Result: A defect was found in the air intake or exhaust system. Repair: Make any necessary repairs. Result: The exhaust system is restricted with white deposits. Repair: Refer to Troubleshooting, "Exhaust System Contains DEF Deposits". Result: No defects found in the air intake or exhaust systems. Contact the Dealer Solution Network (DSN).