SFWR GP-A1000 4869407 - Caterpillar

Probable Causes
NOx Reduction System cooler leak
Aftertreatment Regeneration Device (ARD) head leaking coolant
Cylinder head gasket leak
Cylinder head leakRecommended Actions
Note: After the repair has been made, an "Aftertreatment System Functional Test" must be performed using Cat® Electronic Technician (ET). The test will verify the proper functionality of both NOx sensors.
Table 1
Troubleshooting Test Steps Values Results
1. Check the NRS Cooler
A. Check the NRS cooler for leaks for utilizing the "On Engine Test Procedure". Refer to Testing and Adjusting, "Exhaust Cooler (NRS) - Test".
NRS Cooler
Result : The NRS cooler does not have a leak.
Proceed to Test Step 2.
Result : The NRS cooler has a leak.
Repair: Replace the NRS cooler.
Proceed to Step 5.
2. Check the ARD Head
A. Pressurize the cooling system. Refer to Systems Operation/Testing and Adjusting, "Cooling System - Test" for the correct procedure.
B. Remove the ARD head.
C. Inspect the combustion can for signs of coolant leaking from the ARD nozzle heater o-ring seals.
Coolant Leak
Result : The ARD head is not leaking coolant.
Proceed to Test Step 3.
Result : The ARD head is leaking coolant.
Repair: Replace the ARD head.
Proceed to Test Step 5.
3. Check for a Cylinder Head Gasket Leak
A. Check the cylinder head gasket for leaks. Refer to the Systems Operation/Testing and Adjusting for the proper procedure for checking the cylinder head.
Cylinder Head Gasket
Result : The cylinder head gasket is not leaking.
Proceed to Test Step 4.
Result : The cylinder head gasket is leaking.
Repair: Replace the cylinder head gasket. Refer to the Disassembly and Assembly manual.
4. Inspect the Cylinder Head
A. Check for cracks in the cylinder head. Perform a leak test on the cylinder head. Refer to the Systems Operation/Testing and Adjusting for the proper procedure for checking the cylinder head.
Cylinder Head
Result : A crack is found in the cylinder head.
Repair: Repair the cylinder head and/or replace the cylinder head
Proceed to Test Step 5.
5. Perform an "Aftertreatment System Functional Test"
A. Start the engine.
B. Connect to the ECM using Cat ET.
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 more codes.
Repair: Troubleshoot the additional codes. Refer to the Troubleshooting manual for the correct procedure.
If 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).