The Electronic Control Module (ECM) detects all of the following conditions:
- Air inlet temperature is equal to 79 °C (174 °F) or greater than 79 °C (174 °F) for more than four seconds.
- The engine has been running more than three minutes. This three minute delay begins once the engine speed is above zero rpm.
System Response:
The ECM will log the diagnostic event. The ECM will derate engine power by three percent for each degree celsius above 79 °C (174 °F). The maximum derate is 80 percent of full power. The ECM will restore full power when the air inlet temperature falls to 77 °C (171 °F) for 20 seconds.
- Low power
- There may be a problem with the aftercooler.
- There may be a problem with the air inlet temperature sensor.
Test Step 1. Check for Diagnostic Codes
- Connect the Caterpillar Electronic Technician (Cat ET) to the service tool connector.
- Turn the keyswitch to the ON position. The engine should be off.
- Check for any active diagnostic codes or logged diagnostic codes.
Expected Result:
No diagnostic codes are present.
Results:
- OK - Proceed to Test Step 2.
- Not OK -
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
Test Step 2. Perform a Check of the Aftercooler
- Perform a check of the aftercooler. Refer to the appropriate topic in Testing and Adjusting for possible causes.
Expected Result:
There are no problems with the aftercooler.
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 -
Repair: Repair the problem.Ensure that the repair eliminates the problem.
STOP