C13 Engines for Caterpillar Built Machines Caterpillar

Exhaust Temperature Is High

Usage:

The Engine Control Module (ECM) monitors the following parameters to calculate an exhaust temperature:

Barometric pressure
Intake manifold air temperature
Engine speed

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 ECM derates the engine 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.

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Table 1
Diagnostic Trouble Codes
CDL Code and Description	Comments
E194 (1) High Exhaust Temperature	The code is logged. Engine power is reduced.
E194 (2) High Exhaust Temperature	The code is logged. Engine power is reduced.
E194 (3) High Exhaust Temperature	The code is logged. Engine power is reduced.

Note: High intake manifold air temperature, high altitude operation, and high engine loads can cause the exhaust temperature to increase to a level that may damage the components of the exhaust system. When this occurs, the ECM derates the engine to reduce the exhaust temperature. This protects the components of the exhaust system from damage.

Probable Causes

Associated codes
Boost Leak
Engine operating conditions
High altitude
Obstructed aftercooler

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Table 2
Troubleshooting Test Steps	Values	Results
1. Check for Boost Leakage A. Apply a light load to the engine and check for boost leakage.	Boost leaks	Result: Boost leakage was not found. Proceed to Test Step 2. Result: Boost leakage was found. Repair: Repair the leaks. If the problem is not resolved, proceed to Test Step 2.
2. Check the Engine Operating Conditions A. Check the histogram to determine if the high exhaust temperature was due to normal operation. B. 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. C. If derates are suspected, reset histogram and return the unit to service. If the histogram repopulates without fault codes, the derate was under normal engine operation.	Operating conditions	Result: The code was not logged during a heavy load. Proceed to Test Step 3. Result: The code was logged during a heavy load. Repair: Reduce the load on the engine. If the problem is not resolved, proceed to Test Step 3.
3. Check the Engine Operating Altitude A. Check the engine operating altitude. Note: High altitudes can cause high exhaust temperatures, consider the operational altitude when troubleshooting a high exhaust temperature. High exhaust temperatures are associated with high operational altitudes. Note: When operating below 5500ft and the ambient temperature is below 30° C (85° F), altitude should not cause a high exhaust temperature derate.	High operational altitudes	Result: The engine was operating at high altitudes. The high exhaust temperature was due to high altitudes. Return the unit to service. Result: The engine was not operating at high altitudes. 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 flow of air or coolant through the aftercooler is adequate.	Obstructed aftercooler	Result: The engine aftercooler was obstructed. Repair: Clear any obstructions.

The procedure did not correct the issue, contact your Cat dealer Technical Communicator (TC). For further assistance, your TC can confer with the Dealer Solutions Network (DSN).