DIAGRAM-WIRING 5N8749 - Caterpillar

Table 1
Diagnostic Trouble Codes    
CDL Code    Code Description    Comments    
E1228(1)     High Intake Manifold Air Differential Temperature     The code indicates that the differential temperature of the intake air into the engine has risen above the programmed threshold.    
Illustration 1 g02129374
Inspection points for the ATAAC
Table 2
Troubleshooting Test Steps    Values    Results    
1. Check the Air-to-Air Aftercooler (ATAAC) for Restrictions (if equipped)
A. Inspect the exterior surface of the ATAAC for excessive buildup of dirt or debris. Also verify that the fins of the ATAAC are not damaged.
   
Restrictions
   
Result: The surface of the ATAAC is not damaged and the ATAAC does not have an excessive buildup of dirt or debris.
Proceed to Test Step 2.
Results: The surface of the ATAAC is damaged or the ATAAC has an excessive buildup of dirt or debris.
Repair: Clean the ATAAC, if necessary. If the ATAAC is damaged, replace the ATAAC.
If the problem still exists, proceed to Test Step 2.
   
2. Check the Operation of the Cooling Fan
A. Verify that the engine cooling fan is working properly.
If the fan is belt driven, verify that the belt tension is adequate. Also, verify that the clutch is operating properly.
If the fan is hydraulically driven, verify that there is no leakage around the motor and that the pressure for the fan is adequate.
   
Cooling Fan
   
Result: The fan drive system is not working properly.
Repair: If the fan is belt driven, perform the necessary adjustments or perform any necessary repairs to the clutch or the belt tensioner. Refer to Testing and Adjusting for details.
If the fan is hydraulically driven, repair any leaks that have been discovered. Ensure that the control system for the fan is operating properly. Refer to Troubleshooting, "Cooling Fan Control - Test" for details.
Verify that the repair eliminated the problem.