CONTROLLER 3174938 - Caterpillar

Which Generate This Code:After the engine has been started for three minutes, the air inlet temperature is greater than 95 °C (203 °F) for more than four seconds.System Response:The Electronic Control Module (ECM) logs the event. The ECM will derate the engine power by three percent for each degree celsius above 95 °C (203 °F). The maximum derate is 20 percent of full power. The ECM will restore full power when the air inlet temperature falls to 92 °C (198 °F) for 20 seconds.
Low powerTest Step 1. Check the Engine
Check for a problem in the engine's air inlet and exhaust systems.
Check for a restriction in the air inlet system. A restriction of the air that is coming into the engine can cause high cylinder temperatures. High cylinder temperatures cause higher than normal temperatures in the cooling system.
Check for a restriction in the exhaust system. A restriction of the air that is coming out of the engine can cause high cylinder temperatures.
If the air inlet system for this application is equipped with an aftercooler, check the aftercooler. A restriction of air flow through the air to air aftercooler can cause overheating. Check for debris or deposits which would prevent the free flow of air through the aftercooler.
Check the operating conditions of the engine.
Consider high ambient temperatures. When ambient temperatures are too high for the rating of the cooling system, there is not enough of a temperature difference between the ambient air and coolant temperatures.
Consider high altitude operation. The cooling capability of the cooling system is reduced at higher altitudes. A pressurized cooling system that is large enough to keep the coolant from boiling must be used.
The engine may be running in the lug condition. When the load that is applied to the engine is too large, the engine will run in the lug condition. When the engine is running in the lug condition, engine rpm does not increase with an increase of fuel. This lower engine rpm causes a reduction in coolant flow through the system.
High cooling system temperatures can cause high air inlet temperatures. Check the cooling system for problems.
Verify that the cooling system is filled with coolant to the proper level. If the coolant level is too low, air may be allowed to enter the cooling system. Air in the cooling system will cause cavitation and a reduction in coolant flow.
Check the quality of the coolant. Refer to the Operation and Maintenance Manual for coolant recommendations.
Check for air in the cooling system. Air can be introduced into the cooling system in different ways. The most common cause of air in the cooling system is the improper filling of the cooling system. Refer to the Operation and Maintenance Manual for the proper filling procedure for your engine.The next likely cause is combustion gas leakage into the cooling system. Combustion gas can be introduced into the cooling system through damaged liner seals, cracks in the liners, a damaged cylinder head, or a damaged cylinder head gasket.
Check the cooling system