PAD 6P4327 - Caterpillar

Probable Causes
Electronic control Module (ECM)
Diagnostic codesAir Inlet and Exhaust System
Blockage of the air inlet and exhaust systemFuel
Fuel injectorsAftercooler (if applicable)
Blockage of the aftercooler (if applicable)Atmospheric Pressure Sensor
Check the power supply to the atmospheric pressure sensor.Recommended Actions
Diagnostic Codes
Connect Cat ET and check for active and/or logged diagnostic codes. Troubleshoot any active diagnostic codes before continuing with this procedure.Blockage of the Air Inlet and Exhaust System
Check for air inlet restrictions and/or leaks. A one degree increase in the inlet manifold temperature will increase the exhaust temperature by approximately three degrees. Check for leaks between the exhaust manifold and the turbocharger. Check for exhaust restrictions.Fuel Injectors
Faulty injectors that deliver too much fuel will increase exhaust temperatures. Connect Cat ET in order to determine if any diagnostic codes for the injector solenoids are present. Perform the "Injector Solenoid Test". Observe that the injector solenoids are being energized on Cat ET. Perform the "Cylinder Cutout Test". Locate the misfiring cylinder. Refer to Troubleshooting, "Injector Solenoid - Test".Blockage of the Aftercooler (if applicable)
Normal intake manifold pressure with high exhaust temperature can be caused by blockage in the aftercooler.If the application has an aftercooler, check the aftercooler for correct operation. Check for blockage in the cores of the aftercooler.Check the Power Supply to the Atmospheric Pressure Sensor
If the atmospheric pressure sensor is not being powered by the 5 volt supply, the output of the sensor may float to a value that is interpreted by the ECM as a high altitude condition. The ECM receives the erroneous value of altitude and the ECM derates the engine. Ensure that the 5 volt supply is present at the harness connector for the atmospheric pressure sensor.