819514A15 Mercury HARNESS ASSEMBLY

Note: Codes are detecting a high exhaust gas temperature, when temperature sensors are normal.Resolve the following active codes before proceeding:
4765-3 or 4765-4 Aftertreatment DOC Intake Gas Temperature: Voltage Above or Below Normal
3243-3 or 3424-4 Aftertreatment DPF Inlet Gas Temperature: Voltage Above or Below Normal
3246-3 or 3246-4 Aftertreatment DPF Outlet Gas Temperature: Voltage Above or Below Normal
Table 2
Troubleshooting Test Steps Values Results
1. Check the Engine Oil Level and Obtain an Oil Sample
A. Check oil level and obtain an oil sample. If the oil level is high, then take an oil sample to check for fuel dilution. Refer to Troubleshooting, Oil Contains Fuel, if fuel is present.
Oil
Result: The engine oil sample shows moitor or action required, then skip to Step 5.
Make the necessary repairs.
Result: The engine oil sample and oil level are OK.
Proceed to Test Step 4.
Result: engine oil level is not at the correct level.
Determine root cause of why the oil level was high or low.
2. Associated Codes
Establish a connection with Caterpillar Electronic Technician (Cat ET).
Codes
Result: Associated codes are active.
Refer to Troubleshooting, "Sensor Signal (Analog, Passive) - Test"
Result: Associated codes are not active.
Proceed to Test Step 3.
3. Turbocharger
A. Check the turbocharger oil seal. If the turbocharger has failed, oil could get into the exhaust system.
B. Check the Condition of the Turbocharger.
Refer to Testing & Adjusting, "Turbocharger - Inspect".
Turbocharger
Result: The turbocharger is not operating properly and/or the condition is NOT OK.
Replace the turbocharger.
Result: The turbocharger is operating properly and the condition is OK.
Proceed to Test Step 4.
4. Check for Proper Installation of all Exhaust Temperature Sensors
Exhaust Temperature Sensor
Result: The exhaust temperature sensors are installed properly.
Proceed to Test Step 5.
Result: The exhaust temperature sensors are not installed properly.
Repair: Remove the exhaust temperature sensors and reinstall properly.
5. Check that the Exhaust Temperature Sensors are Operating Correctly
Exhaust Temperature Sensor
Result: The exhaust temperature sensors are operating correctly.
Proceed to Test Step 6.
Result: The exhaust temperature sensors are not operating correctly.
Repair: Refer to “Sensor Signal (Analog, Passive) - Test”.
6. Check Exhaust Gas Temperature in Cat® ET
A. Check Exhaust Gas Temperature
Do not check temperatures until Cat® ET shows that the temperatures are below 300° C (572° F). The temperature should be checked at the areas that are not insulated on the aftertreatment.
B. Compare the actual exhaust temperature with a heat gun to the temperature that is listed in Cat® ET.
Exhaust Gas Temperature
Result: The exhaust gas temperature is approximately the same.
Proceed to Test Step 7.
Result: If the temperatures are not approximately the same, then check the temperature sensor.
Refer to Troubleshooting, "Sensor Signal (Analog, passive) - Test" for the correct resistance.
7. Check the condition of the Air Filter
Air Filter
Result: The air filter is clean and is in good condition.
Proceed to Test Step 8.
Result: The air filter is dirty and is in bad condition.
Repair: Replace the air filter.
8. Air Intake System
A. Check the air intake system.
Refer to the Systems Operation/Testing and AdjustingKENR9884"Air Inlet and Exhaust System - Inspect"
Air Inlet
Result: The air intake system is not restricted.
Proceed to Test Step 9.
Result: The air intake system is restricted.
Make the necessary repairs.
9. Check that all Air Inlet Hoses are Installed Properly
Air Inlet Hoses
Result: The air inlet hoses are installed properly.
Proceed to Test Step 10.
Result: The air inlet hoses are not installed properly.
Repair: Remove the air inlet hoses and inspect for any damage. Then reinstall the air inlet hoses properly.
10. Check the Low-Pressure Fuel System
Note: Refer to Systems Operation/Testing and Adjusting, Fuel System, for additional information.
A. Visually check the fuel level in the fuel tank. Do not rely on the fuel gauge only.
B. Ensure that the vent in the fuel cap is not filled with debris.
C. Inspect the fuel system for external leaks. Ensure that there is no air in the clear bowl on the primary fuel filter.
D. Check that there are no external leaks, no air in the clear primary fuel filter. Change the primary fuel filter and the inline filter for the fuel transfer pump.
E. Check fuel quality. Refer to Systems Operation/Testing and Adjusting, Fuel Quality - Test, for the proper procedure. Check the fuel tank for debris or foreign objects which may block the fuel supply.
F. Check for the proper operation of the fuel transfer pump. Replace the pre-filter if excessive contamination or if the maintenance interval is exceeded. Refer to Systems Operation/ Testing and Adjusting, Fuel System, for test information.
Fuel System
Result: The low-pressure fuel system is OK.
Result: The low-pressure fuel system is NOT OK.
Repair: Replace the fuel transfer pump and the fuel filters. Clean the primary filter/ water separator of debris. Refer to the Operation and Maintenance Manual for details.
STOP Complete the procedure in the order in which the steps are listed.If the procedure corrected the issue, Return the engine to service.If the procedure did not correct the issue, Contact your Caterpillar dealer Technical Communicator (TC). For further assistance, your TC can confer with the Dealer Solutions Network (DSN).High Exhaust Gas Temperature After Emergency High Temperature Diagnostic Code