WASHER 8T8890 - Caterpillar

Use this procedure in order to troubleshoot a high inlet air temperature, or use this procedure if one of the following event codes is active. Refer to Troubleshooting, "Event Code List" for information about event codes and the default trip points for these codes. You must access the monitoring system on Caterpillar Electronic Technician (ET) in order to view the current trip points for these codes.
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 programmed trip point for the specified delay time. The code is logged.
E025 (2) High Inlet Air Temperature Derate The code is logged. Engine power is derated. 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
Table 2
Troubleshooting Test Steps Values Results
1. High Ambient Air Temperature
A. Determine if the ambient air temperature is within the design specifications for the cooling system.
Air
temperature
Result: The ambient air temperature is within specification.
Proceed to Test Step 2.
Result: The ambient air temperature is NOT within specification.
Determine the cause of the high air temperature. Make corrections when possible.
2. Coolant Temperature
Temperature
Troubleshooting, "Coolant Temperature Is High"
3. Check for High Inlet Air Restriction
When the inlet air pressure is low, the turbocharger works harder in order to achieve the desired inlet air pressure. This increases are inlet temperature.
A. Measure the inlet air pressure while the engine is operating under load. Refer to Technical Marketing Information (TMI), for specific data.
Inlet air restriction
Result: The inlet air pressure is within the listed specification.
Proceed to Test Step 4.
Result: The inlet air pressure is NOT within listed specification.
Check for plugged air filters. Check for obstructions to the air inlet. Make the necessary repairs. Verify that the problem is resolved.
4. Check the Inlet Manifold Air Temperature Sensor and/or the Circuit
A. Remove the sensor. Compare the reading for the inlet air temperature and the ambient air temperature.
Inlet manifold air temperature sensor
Result: The sensor is OK.
Proceed to Test Step 5.
Result: The sensor is NOT OK.
If the readings are not approximately equal, switch the sensor with a sensor that is known to be good. Replace any faulty components.
5. Check for Sufficient Flow of Cooling Water Through the Aftercooler
A. Check the inlet temperature of the coolant for the aftercooler. Compare the reading to the regulated temperature.
B. Check the outlet temperature of the coolant.
A high indicates an insufficient flow rate.
C. Check for obstructions
D. Check the water pump for proper operation. Systems Operation/Testing and Adjusting, "Water Pump - Test"
Coolant flow
Result: There is NOT a high temperature differential between the inlet temperature and the outlet temperature of the coolant for the aftercooler.
Proceed to Test Step 6.
Result: There is a high temperature differential between the inlet temperature and the outlet temperature of the coolant for the aftercooler.
Make repairs, if necessary. Verify that the problem is resolved.
6. Check for Sufficient