C4.4 Marine Generator Set Caterpillar

The Electronic Control Module (ECM) monitors the temperature sensor in the outlet from the turbocharger.

Certain operating conditions may cause the exhaust temperature to increase to a level that may damage engine components. If a high exhaust temperature occurs, the ECM derates the engine in order to reduce the exhaust temperature. The engine is derated only to a level that allows the exhaust temperature to return to an acceptable level.

Table 1

Diagnostic Codes for High Exhaust Temperature
J1939 Code	Code Description	Comments
173-15	Engine Exhaust Gas Temperature : High - least severe (1)	The ECM has been powered for at least 2 seconds. The engine has been running for at least 10 seconds. There are no diagnostic trouble codes for the exhaust gas temperature sensor. There are no diagnostic trouble codes for the 5 VDC supply.
173-16	Engine Exhaust Gas Temperature : High - moderate severity (2)	The ECM has been powered for at least 2 seconds. The engine has been running for at least 10 seconds. There are no diagnostic trouble codes for the exhaust gas sensor. There are no diagnostic trouble codes for the 5 VDC supply. The engine will be derated.
173-0	Engine Exhaust Gas Temperature : High - most severe (3)	The ECM has been powered for at least 2 seconds. The engine has been running for at least 10 seconds. There are no diagnostic trouble codes for the exhaust gas sensor. There are no diagnostic trouble codes for the 5 VDC supply. The engine will be derated.

Probable Causes

• Inlet system leak

• Engine operating conditions

• High altitude

• Obstructed heat exchanger or Air-to-Air Aftercooler (ATAAC)

Complete the procedure in the order in which the steps are listed.

Table 2

Troubleshooting Test Steps	Values	Results
1. Check for Inlet System Leakage A. Apply a light load to the engine and check for leakage from the inlet system downstream of the turbocharger.	Inlet system leaks	Result: Leakage was found. Repair the leaks. Return the unit to service. Result: Leakage was not found. Proceed to Test Step 2.
2. Check the Engine Operating Conditions A. Use the electronic service tool to check the histograms. Use the histograms to determine if the high exhaust temperature occurred during normal operation. If possible, interview the operator. Determine if the engine is being operated under heavy load. Ensure that the engine is being operated at an acceptable engine speed. If derates are suspected, reset the histogram and return the unit to service. If the histogram repopulates without fault codes, the derating of the engine was under normal engine operation.	Type of operation	Result: The code was logged during a heavy load. Reduce the load on the engine. Return the unit to service. Result: The code was not logged during a heavy load. Proceed to Test Step 3.
3. Check for an Obstructed Exhaust Manifold Cooler A. The exhaust gas temperature can increase if the coolant flow through the exhaust manifold cooler is obstructed. Check the coolant passages in the exhaust manifold cooler for obstructions or debris. Ensure that the flow of coolant through the exhaust manifold cooler is adequate.	Obstructed exhaust manifold cooler	Result: The flow of coolant through the exhaust manifold cooler is obstructed. Clear any obstructions. Return the unit to service. Result: The exhaust manifold cooler is not obstructed. Contact the Technical Communicator at a Cat dealer.
4. Check for an Obstructed ATAAC A. The intake manifold air temperature can increase if the flow through the ATAAC is obstructed. Check the ATAAC for obstructions or debris. Ensure that the flow of air through the ATAAC is adequate.	Obstructed ATAAC	Result: The ATAAC was obstructed. Clear any obstructions. Return the unit to service. Result: The ATAAC was not obstructed. Contact the Technical Communicator at a Cat dealer.