CONTROLLER 4315792 - Caterpillar

Probable Causes
Codes
Intake air temperature
Inlet air restriction
Engine overload
Exhaust restriction
Air/Fuel Ratio
Valve lash
Excessive depositsRecommended Actions
Table 6
Troubleshooting Test Steps Values Results
1. Check for Codes
A. Connect Cat® Electronic Technician (ET) to the service tool connector.
B. Look for active codes that are associated with the system for the event code.
Codes
Result: An associated code is active.
Repair: Troubleshoot any associated codes before continuing with this test.
Result: A code is active or logged.
Proceed to Test Step 2.
2. Check for High Intake Manifold Air Temperature
Note: A 1 degree increase in the inlet manifold temperature will increase the exhaust temperature by approximately 3 degrees.
A. Refer to Troubleshooting, "Intake Manifold Air Temperature Is High" for additional information.
Temperature
Result: The intake manifold air temperature is OK.
Proceed to Test Step 3.
Result: The intake manifold air temperature is NOT OK.
Repair: Determine the cause of the high intake manifold air temperature and correct the problem.
If the problem is not resolved, proceed to Test Step 3.
3. Check for a Restriction in the Inlet Air System
Note: Inlet air restriction can cause uneven exhaust port temperatures.
A. Check the air filter restriction indicator, if equipped. Refer to the Operation and Maintenance Manual for additional information.
B. Refer to Troubleshooting, "Inlet Air Is Restricted" for additional information.
Note: High cylinder temperatures can cause a high coolant temperature.
Restriction
Result: The inlet air restriction is OK.
Proceed to Test Step 4.
Result: The inlet air restriction is NOT OK. An imbalance in the system is discovered.
Repair: Repair or replace damaged inlet air system components. Equalize the inlet air restriction for each of the turbochargers.
If the problem is not resolved, proceed to Test Step 4.
4. Check for Engine Overload
Note: When the load that is applied to the engine is too large, the engine will run in the lug condition. When the engine is running in the lug condition, engine rpm will try to maintain rated speed but the load applied may cause the engine speed to be lower.
Load
Result: The engine is not being overloaded.
Proceed to Test Step 5.
Result: The engine is being overloaded.
Repair: Reduce engine load to an acceptable limit.
If the problem is not resolved, proceed to Test Step 5.
5. Check for a Restriction in the Exhaust System
Note: A restriction of the exhaust can cause high cylinder temperatures.
A. Measure the exhaust restriction during engine operation with a load. For data that is specific to your engine, refer to the Technical Marketing Information (TMI).
Restriction
Result: The exhaust restriction measures OK.
Proceed to Test Step 6.
Result: The exhaust restriction measurement is NOT OK.
Repair: Repair or replace damaged exhaust system components.
If the problem is not resolved, proceed to Test Step 6.
6. Check the Air/Fuel Ratio
Note: An air/fuel mixture that is too rich will increase the exhaust temperature. A change in the fuel energy content will change the air/fuel ratio.
Note: If the setting for the fuel LHV is too low, the air/fuel ratio will be too rich.
A. Obtain a fuel analysis.
Note: If the quality of the gas is inconsistent, obtain several analyses over a time.
B. Enter the data into Caterpillar Software , "Gas Engine Ratings Pro (GERP)".
C. Verify that the fuel supply pressure is