815037 Mercury PLUG

Table 1
Diagnostic Trouble Codes
CDL Code Code Description
(code descriptions may vary) 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.
Follow the troubleshooting procedure in order to identify the root cause of the problem. 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 in order to reduce the exhaust temperature. This protects the components of the exhaust system from damage.Probable Causes
Associated codes
Boost Leak
Engine operating conditions
Failed exhaust balance valve
High altitude
Obstructed aftercooler
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 found.
Repair the leaks. Return the unit to service.
Result: Boost leakage was not found.
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.
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 derate was under normal engine operation.
Normal 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 the Exhaust Balance Valve
A. An exhaust balance valve that has failed in the closed position can cause high exhaust temperatures, Refer to Troubleshooting, "Exhaust Balance Valve - Test" for the correct troubleshooting procedure.
Failed exhaust balance valve
Result: The exhaust balance valve has failed.
Repair or replace the balance valve. Return the unit to service.
Result: The exhaust balance valve has not failed.
Proceed to Test Step 4.
4. Check the Engine Operating Altitude
A. Check the engine operating altitude.
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.
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 5.
5. 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.
Clear any obstructions. Return the unit to service.
Complete the procedure in the order in which the steps are listed.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).