SEAL TO AFTERCOOLER ELBOW 5H1039 - Caterpillar

Use this procedure in order to troubleshoot a problem with a high differential pressure across the Clean Emissions Module (CEM). The pressure is measured between the engine exhaust intake for the CEM and the treated exhaust leaving the CEM.
Table 1
J1939 Code and Description CDL Code and Description Comments
4358-15
Aftertreatment #1 SCR Catalyst Exhaust Gas Differential Pressure : High - least severe (1) E942 (1)
High Aftertreatment #1 SCR Catalyst Differential Pressure The code is logged.
Dosing is disabled until the pressure is correct. Probable Causes
Codes
Exhaust System
SCR CatalystRecommended Actions
Table 2
Troubleshooting Test Steps Values Results
1. Check for Codes
A. Turn the DC breaker to the ON position.
B. Establish communication between Cat® Electronic Technician (ET) and the Electronic Control Module (ECM).
C. Look for active codes that are associated with the system for the event code.
Codes
Result: A code other than the E942 or 4358-15 is present.
Repair: Troubleshoot any associated codes before continuing with this test.
Result: An E942 or 4358-15 code is present.
Proceed to Test Step 2.
2. Visually Inspect the Exhaust System For Damage
A. Turn the DC breaker to the OFF position.
B. Visually inspect the exhaust system for damage between the SCR catalyst outlet and the tailpipe outlet.
Damage
Result: A damaged component was found in the exhaust system.
Repair: Repair or replace the damaged component.
Verify that the repair eliminated the problem. Return to service.
Result: No damage was found in the exhaust system.
If the problem is not resolved, proceed to Test Step 3.
3. Inspect the SCR Catalyst
A. Turn the DC breaker to theOFF position.
B. Inspect the face of the SCR catalyst.
C. Check for oil, fuel, urea deposits, or soot buildup on the SCR catalyst face.
Deposits/Buildup
Result: The SCR catalyst face has oil, fuel, urea deposits, or soot buildup.
Repair: Replace the damaged catalyst. Refer to Special Instruction, REHS9690, "Aftertreatment Filter Maintenance on Large Engine Tier 4 Interim and Final Products Equipped with a Selective Catalyst Reduction (SCR) Filter" for the SCR reset procedure.
For oil, refer to Troubleshooting,, "Exhaust System Contains Oil".
For fuel, refer to Troubleshooting,, "Exhaust System Contains Fuel".
For urea deposits, refer to Troubleshooting,, "NOx Conversion is Low".
For soot buildup, refer to Troubleshooting,, "Exhaust Has Excessive Black Smoke".
Verify that the repair eliminated the problem.
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).