WHEEL GP-FRONT 8X6474 - Caterpillar

Probable Causes
NOx Reduction System (NRS) cooler
Cylinder head gasket
Cylinder head
Cylinder blockRecommended Actions
Note: The procedures have been listed in order of probability. Complete the procedures in order.Note: After the repair has been made, the electronic service tool must be used to perform an "Aftertreatment System Functional Test". The test will verify the correct functionality of both NOx sensors and the catalysts.
Table 1
Troubleshooting Test Steps Values Results
1. NRS cooler
A. Check the NRS cooler for leaks by utilizing the "On Engine Test Procedure". Refer to Systems Operation, Testing, and Adjusting, "Exhaust Cooler (NRS) - Test".
NRS cooler
Result : The NRS cooler has a leak.
Repair: Replace the NRS cooler. Refer to the Disassembly and Assembly manual for the correct procedure.
Proceed to Step 5.
Result : The NRS cooler does not have a leak.
Proceed to Test Step 2.
2. Cylinder Head Gasket
A. Remove the cylinder head. Refer to Disassembly and Assembly, "Cylinder Head - Remove".
B. Inspect the cylinder head gasket for faults and any signs of leakage.
Cylinder head gasket
Result: The cylinder head gasket does not show signs of damage or leakage.
Repair: Install a new cylinder head gasket and install the cylinder head. Refer to Disassembly and Assembly, "Cylinder Head - Install" .
Result: The cylinder head gasket shows signs of damage or leakage.
Proceed to Test Step 3.
3. Cylinder Head
A. Check for cracks in the cylinder head. Perform a leak test on the cylinder head. Refer to System Operation, Testing and Adjusting, "Cylinder Head - Inspect" for the correct procedure.
Cylinder head
Result: A fault was found in the cylinder head.
Repair: Repair the cylinder head or replace the cylinder head. Install the cylinder head. Refer to Disassembly and Assembly, "Cylinder Head - Install".
Result: A fault was not found in the cylinder head.
Proceed to Test Step 4.
4. Cylinder Block
A. Inspect the top face of the cylinder block for faults and signs of leakage.
Refer to Systems Operation, Testing, and Adjusting, "Cylinder Block - Inspect" for the correct procedure.
Cylinder block
Result: A fault was found in the cylinder block.
Repair: Repair the cylinder block or replace the cylinder block. Inspect the top deck. Refer to the Reuse and Salvage Guidelines for the proper inspection procedure.
Result: No fault was found in the cylinder block.
Install the cylinder head. Refer to Disassembly and Assembly, "Cylinder Head - Install".
Contact the Dealer Solutions Network (DSN).
5. Perform an "Aftertreatment System Functional Test"
A. Start the engine.
B. Connect the electronic service tool to the diagnostic connector.
C. Navigate to "Diagnostics Tests".
D. Perform the "Aftertreatment System Functional Test".
System test
Result : The test is successful.
Return the engine to service.
Result : The test is not successful.
There are additional diagnostic codes.
Repair: Troubleshoot the additional codes. Refer to Troubleshooting, "Diagnostic Trouble Codes" or Troubleshooting, "Event Codes"for the correct procedure.