HARNESS AS-PANEL 2027746 - Caterpillar

Probable Causes
Diagnostic codes
Starting aids
Water temperature regulators
Unit injectors
Personality module (flash file)
Fuel supply
Cooling system
Component wearRecommended Actions
Diagnostic Codes
Check for active diagnostic codes on the Caterpillar Electronic Technician (Cat ET). Troubleshoot any active codes before continuing with this procedure.Starting Aids
Air Inlet Heater
Make sure that the air inlet heater is programmed to On. For additional information on the air inlet heater, refer to Troubleshooting, "Air Inlet Heater Circuit - Test".Water Temperature Regulators
Check the water temperature regulators for correct operation. Refer to Testing and Adjusting, "Cooling System" for the proper procedure. If necessary, replace the water temperature regulators. Refer to Disassembly and Assembly, "Water Temperature Regualtor - Remove and Install".Unit Injectors
Use the Caterpillar Electronic Technician (Cat ET) to perform the cylinder cutout test. Try to simulate the conditions for the test that were experienced during operation. Cut out each cylinder individually for approximately one minute in order to isolate any misfiring cylinders. If the misfire can be isolated to a specific cylinder, proceed to Troubleshooting, "Injector Solenoid Circuit - Test".Personality Module (Flash File)
Verify that the correct personality module (flash file) is installed. The personality module (flash file) that is installed in the ECM will be displayed on the "Configuration" screen of the Caterpillar Electronic Technician (Cat ET).Fuel Supply
Monitor the exhaust for smoke while the engine is being cranked.If no smoke is present, there may be a problem with the fuel quality or there may be a problem with the fuel supply.
Check the fuel quality. Refer to Testing and Adjusting, "Fuel Quality - Test" and Special Instruction, SEBD0717, "Diesel Fuels And Your Engine".
Check the fuel pressure. Refer to Testing and Adjusting, "Fuel System Pressure - Test".
Ensure that the fuel system has been primed. Refer to Testing and Adjusting, "Fuel System - Prime".
Check for fuel supply lines that are restricted.
If the temperature is below 0 °C (32 °F), check for solidified fuel (wax).
Check for air in the fuel system. Refer to Testing and Adjusting, "Air in Fuel - Test".Cooling System
Check for an internal coolant leak. Check for coolant in the engine oil, coolant in the cylinders, and coolant in the exhaust system. Refer to the Systems Operation, "Testing and Adjusting".Component Wear
Check the following components for excessive wear:
Valves
Pistons
Rings
Cylinder walls