ENGINE AR-PRIMARY 4639823 - Caterpillar

Table 1
Event Code
Description Conditions which Activate the Code System Response
E027 (1) High Inlet Air Temperature Warning The inlet air temperature has exceeded the trip point and the delay time has expired. The alarm output is activated. The code is logged.
E368 (1) High Inlet Air Temperature Warning
E025 (2) High Inlet Air Temperature Derate The alarm output is activated. The code is logged. Engine power is derated.
E368 (2) High Inlet Air Temperature Derate
E026 (3) High Inlet Air Temperature Shutdown The shutdown output is activated. The code is logged. The engine is shut down.
E368 (3) High Inlet Air Temperature Shutdown Note: Refer to Troubleshooting, "Engine Monitoring System" for information on trip points and delay times.Probable Causes
High ambient air temperature
High coolant temperature
High inlet air restriction and/or high altitude
Faulty inlet air temperature sensor and/or circuit
Insufficient flow of cooling water through the aftercooler
Insufficient flow of air through the aftercoolerRecommended Repairs
High Ambient Air Temperature
Determine if the ambient air temperature is within the design specifications for the cooling system.Determine the cause of the high air temperature. Make corrections, when possible.Coolant Temperature
Refer to Troubleshooting, "Coolant Temperature Is High".Check for High Inlet Air Restriction and/or High Altitude
When inlet air pressure is low, the turbocharger works harder in order to achieve the desired inlet air 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.Inlet Air Restriction
Check for plugged air filters. Check for obstructions to the air inlet. Replace the air filters and/or remove the obstruction from the air inlet.High Altitude
Make sure that the settings for the engine are correct for the altitude.Check the Inlet Manifold Air Temperature Sensor and/or the Circuit
Allow the sensor to cool. Remove the sensor. Compare the reading for the inlet air temperature and the ambient air temperature. The sensor is OK if the readings are approximately equal.If the readingsare not approximately equal, switch the sensor with a sensor that is known to be good. Replace any faulty components.Check for Sufficient Flow of Cooling Water Through the Aftercooler
Check the inlet temperature of the coolant for the aftercooler. Compare the reading to the regulated temperature. If the temperature is OK, check the outlet temperature of the coolant. A high temperature differential indicates an insufficient flow rate.If there is a high differential between the inlet temperature and the outlet temperature of the coolant for the aftercooler, perform the following procedures:
Check the water circuit of the aftercooler for obstructions.
Check the pump for proper operation.
Make repairs, if necessary.Check for Sufficient Flow of Air Through the Aftercooler
Determine the pressure differential of the inlet air across the aftercooler. For specific data, refer to the Technical Marketing Information for the engine.If the pressure differential of the air across the aftercooler does not match the specifications, clean the aftercooler.