GUIDE 8P4303 - Caterpillar

Note: Refer to Troubleshooting, "Cat ET Service Features" for information about service features.Probable Causes
Engine operation
Diagnostic codes, event codes and derates
Fuel quality
Fuel injection
Engine speed/timing
Air inlet and exhaust system
Check for damaged accessory equipmentRecommended Actions
Note: The procedures have been listed in order of probability. Complete the procedures in order.
Table 1
Troubleshooting Test Steps     Values     Results    
1. Engine Operation
A. Use Cat® Electronic Technician (ET) to check the "Current Totals" for excessive idle time and/or for a high load factor. Excessive idle time and/or for a high load factor would be indicative of poor operating habits.
   
Operation    
Result: Excessive idling is indicated.
Repair: Make the necessary changes. Ensure that the problem is resolved.
Result: Excessive idling is not indicated.
Proceed to Test Step 2.    Note: Fuel consumption may also be affected by environmental conditions such as wind and snow.
Table 2
Troubleshooting Test Steps     Values     Results    
2. Diagnostic Codes, Event Codes and Derates
Certain diagnostic codes and/or event codes may cause poor performance.
A. Connect Cat ET and download the "Warranty Report" from the engine Electronic Control Module (ECM) before performing any troubleshooting or clearing diagnostic trouble codes.
B. Wait at least 30 seconds in order for any codes to become active.
   
Codes and Derates    
Result: Codes are active.
Repair: Troubleshoot the codes that are present.
Proceed to Test Step 3.
Result: No codes are active.
Proceed to Test Step 3.
   Note: Certain failure modes of a sensor may produce an output signal that does not represent an accurate measurement. The inaccurate measurement can occur when the signal is in the operational range of the sensor. Use Cat ET to check that the pressures and the temperatures are fluctuating normally. Also check that the values are reasonable for the conditions that are present.
Table 3
Troubleshooting Test Steps     Values     Results    
3. Fuel Quality
A. Check fuel quality.
Cold weather adversely affects the characteristics of the fuel.
   
Fuel Quality    
Result: Fuel quality is undesirable.
Repair: Refer to the Operation and Maintenance Manual for information on improving the characteristics of the fuel during cold-weather operation. Ensure that the problem is resolved.
Result Fuel quality is desirable.
Proceed to Test Step 4.
   
Contact with high pressure fuel may cause fluid penetration and burn hazards. High pressure fuel spray may cause a fire hazard. Failure to follow these inspection, maintenance and service instructions may cause personal injury or death.
Table 4
Troubleshooting Test Steps     Values     Results    
4. Fuel Injection
A. Perform the "Fuel System Verification Test" in Cat ET. Refer to Troubleshooting, "Injector Solenoid - Test".
   
Fuel Injection    
Result The "Fuel System Verification Test" failed.
Repair: Diagnose the problem and then repair the problem. Clear all logged diagnostic codes. Verify that the repair eliminated the problem.
Result The "Fuel System Verification Test"