LINK AS 7T4761 - Caterpillar

The Electronic Control Module (ECM) detects a problem with the engine's intake manifold air temperature. Information on default settings and ranges for this event can be found in troubleshooting with an event code Troubleshooting, "Event Codes".System Response:The event code will be logged.Possible Performance Effect:E539(1)
There are no performance effects.E539(2)
The engine power will be derated.TroubleshootingIntake manifold air temperature can be high for the following reasons:
High ambient air temperature
High inlet air restriction and/or high altitude
Restriction in the exhaust system
Faulty inlet air temperature sensor and/or circuitTest Step 1. Perform the following Inspections
Check for High Ambient Air Temperature
Determine if the ambient air temperature is within the design specifications for the inlet air system. When ambient temperatures are too high for the rating of the inlet air system, there is not enough of a temperature difference between the ambient air and inlet air temperatures.
Determine the cause of the high inlet air temperature. Correct the situation, when possible.
Check for High Inlet Air Restriction and/or High Altitude Operation When inlet air pressure is low, the turbocharger works harder in order to achieve the desired inlet manifold pressure. This increases inlet air temperature.
Measure the inlet air pressure while the engine is operating under load. For specific data, refer to the Technical Marketing Information for the engine.
Check for plugged air filters. Check for obstructions to the air inlet. A restriction of the air that enters the engine can cause high cylinder temperatures. High cylinder temperatures cause higher than normal temperatures in the cooling system.
Replace the air filters and/or remove the obstruction from the air inlet.
Consider high altitude operation. The cooling capability of the cooling system is reduced at higher altitudes. A pressurized cooling system that has been designed for the higher altitudes must be used. Ensure that the engine is configured for high altitude operation.
Check for Exhaust System Restriction 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.Expected Result:A problem has been found in the inlet air system and/or the related engine systems.Results:
OK - A thorough inspection revealed a problem.Repair: Repair the problem.STOP
Not OK - A thorough inspection did not reveal a problem.Repair: Connect Caterpillar Electronic Technician (ET) to the service tool connector. Check Cat ET for active/logged diagnostic codes related for the inlet air system. If an active/logged code is found, refer to the appropriate troubleshooting procedure.STOP