CORE AS-OIL COOLER 3488094 - Caterpillar

Which Generate This Code:The engine's Electronic Control Module (ECM) detects the following condition:
Atmospheric pressure that is less than 77 kPa (11 psi)System Response:The ECM will log the event. The ECM will derate the engine in increments of one percent per 1 kPa (0.15 psi). The engine may be derated to a maximum of 19 percent.
Low power
There may be a problem with the atmospheric pressure sensor.
The engine is being operated at a high altitude.Test Step 1. Check for Diagnostic Codes
Connect Caterpillar Electronic Technician (ET) to the service tool connector.
Turn the keyswitch to the ON position.
Check for any active diagnostic codes.Expected Result:There are no active diagnostic codes.Results:
OK - There are no active diagnostic codes.Repair: The engine is being operated at a high altitude.STOP
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.STOP