KEY 7Y5270 - Caterpillar

Use this procedure in order to troubleshoot an occurrence of a high exhaust temperature. Also, use this procedure if one of the following event codes is active.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
Event Codes    
Code and Description    Conditions which Generate this Code    System
Response    
E278(1)
High Exhaust Differential Temperature - least severe     The differential temperature for the exhaust is above the trip point temperature     The code is logged.    
E278(2)
High Exhaust Differential Temperature - moderate severity    
E278(3)
High Exhaust Differential Temperature - most severe    
E321(1)
High Right Exhaust Temperature - least severe     The manifold exhaust temperature has exceeded the trip point for the programmed delay time.     The code is logged.    
E321(2)
High Right Exhaust Temperature - moderate severity    
E321(3)
High Right Exhaust Temperature - most severe    
E322(1)
High Left Exhaust Temperature - least severe    
E322(2)
High Left Exhaust Temperature - moderate severity    
E322(3)
High Left Exhaust Temperature - most severe    
1318-15
Engine Exhaust Temperature Bank Imbalance : High - least severe (1)     The differential temperature for the exhaust is above the trip point temperature     The code is logged.    
1318-16
Engine Exhaust Temperature Bank Imbalance : High - moderate severity (2)    
1318-0
Engine Exhaust Temperature Bank Imbalance : High - most severe (3)    
2433-16
Engine Exhaust Gas Temperature - Right Manifold: High -moderate severity (2)     The manifold exhaust temperature has exceeded the trip point for the programmed delay time.     The code is logged.
The alarm output is activated.    
2433-0
Engine Exhaust Gas Temperature - Right Manifold: High - most severe (3)    
2434-16
Engine Exhaust Gas Temperature - Left Manifold: High - moderate severity (2)    
2434-0
Engine Exhaust Gas Temperature - Left Manifold: High - most severe (3)    Probable Causes
Diagnostic codes
Air inlet and exhaust system
Engine operating conditions
Fuel Injectors
Obstructed aftercooler
Separate Circuit Aftercooler (SCAC) temperature regulatorsRecommended 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 Diagnostic Codes
A. Establish communication between Caterpillar® Electronic Technician (Cat 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.
   
Associated diagnostic codes
   
Result: A diagnostic code is active or logged.
Repair: Troubleshoot any codes before continuing with this procedure.
Verify that the repair eliminated the problem.
Result: A diagnostic 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