BASE AS 1181461 - Caterpillar

Use this procedure in order to troubleshoot an occurrence of a high exhaust temperature. Also, use this procedure if one of the following diagnostic codes is active or easily repeated.Certain operating conditions may cause the calculated exhaust temperature to increase to a level that may damage engine components. If a high exhaust temperature occurs, the Electronic Control Module (ECM) derates the engine in order to reduce the calculated exhaust temperature. The engine is derated only to a level that allows the calculated exhaust temperature to return to an acceptable level.
Table 1
Engine Event
J1939 Code and Description Conditions which Generate this Code System
Response
173-15 Engine Exhaust Gas Temperature : High - least severe The exhaust temperature is above the trip point temperature The code is logged.
The alarm output is activated.
2789-16 Engine Turbocharger 1 Calculated Turbine Inlet Temperature : High - moderate severity The calculated turbine inlet temperature is above the trip point The code is logged.
The engine is derated Probable Causes
Event codes
Air inlet and exhaust system
Engine operating conditions
Obstructed aftercoolerRecommended Actions
Note: The procedures have been listed in order of probability. Complete the procedures in the order of the listed test steps.
Table 2
Troubleshooting Test Steps Values Results
1. Check for Active Codes or Logged Codes
A. Establish communication between Cat® Electronic Technician (ET) and the ECM . Refer to Troubleshooting, "Electronic Service Tools", if necessary.
B. Monitor the diagnostic codes on Cat ET. Determine if a code is active or logged.
Note: Wait at least 30 seconds in order for diagnostic codes to become active.
Codes
Result: A code is active or logged.
Repair: Troubleshoot any codes before continuing with this procedure.
Result: A code is not active or logged.
Proceed to Test Step 2.
2. Check the Air Inlet and Exhaust System for Problems
A. Check for an air filter restriction. Clean plugged air filters or replace plugged air filters.
B. Check the air inlet and exhaust system for restrictions and/or leaks.
C. Check the performance of the turbocharger. Ensure that recommended maintenance is performed on the turbocharger.
Air Inlet and Exhaust System
Result: The air filter, air inlet system, exhaust system, and turbocharger are OK.
Proceed to Test Step 3.
Result: The air filter is restricted, air inlet and/or exhaust system are NOT OK.
Repair: Repair or replace any necessary components..
If the problem is not resolved, proceed to Test Step 3.
3. Check the Engine Operating Conditions
A. Check the histogram to determine if the high exhaust temperature was due to normal operation.
When possible, interview the operator. Determine if the engine is being operated under heavy load. Ensure that the engine is being operated at the proper engine speed.
If derates are suspected, reset histogram and return the unit to service. If the histogram repopulates without fault codes, the engine was under normal operation.
Normal Operation
Result: The code was logged during a heavy load.
Repair: Reduce the load on the engine.
Result: The code was not logged during a heavy load.
Proceed to Test Step 4.
4. Check for an Obstructed Aftercooler
A. The intake manifold air temperature can increase if the flow through the aftercooler is obstructed. Check the aftercooler for obstructions or debris. Ensure that the