SEAL AS 3871379 - Caterpillar

Conditions Which Generate This Code:The Electronic Control Module (ECM) detects the following condition:
The aftercooler temperature is greater than the default temperature of 102 °C (216 °F) for 5 seconds.
The diagnostic codes 279-03 and 279-04 are not active.System Response:The ECM will log the event. The warning is deactivated if the temperature decreases below 99 °C (210 °F) for 2 seconds.
None
There may be a problem with the aftercooler.
There may be a problem with the aftercooler temperature sensor.Test Step 1. Check for "ACTIVE" Diagnostic Codes.
Start the Caterpillar Electronic Technician (ET).
Turn the main power to the ON position. The engine should be OFF.
Check for any Active Diagnostic Codes or Logged Diagnostic Codes.Expected Result:There should be no diagnostic codes that are present.Results:
OK - There are no diagnostic codes that are present. Proceed to test step 2.
Not OK - There are diagnostic codes that are present.Repair: Repair the diagnostic codes that are present. Refer to the appropriate topic in the "Troubleshooting With a Diagnostic Code" section of this manual. Ensure that the repair eliminates the problem.STOPTest Step 2. Perform a Check of the Cooling System.
Perform a check of the cooling system. Refer to the diagnostic procedure Troubleshooting, "Coolant Temperature is Too High" for possible causes.Expected Result:There are no problems with the cooling system.Results:
OK - There may be an intermittent problem.Repair: Monitor the operation of the engine. Repair the problem. Ensure that the repair eliminates the problem.STOP
Not OK - There is a problem with the cooling system.Repair: Repair the problem. Ensure that the repair eliminates the problem.STOP