SEAL 8H9155 - Caterpillar

The probable cause of low inlet pressure of the Diesel Particulate Filter (DPF) is an exhaust leak.Use this procedure if the following event code is active. Refer to Troubleshooting, "Event Codes" for information about event codes.Note: Some of the following codes may not be applicable for certain applications.Clear all "Active" codes using Cat ET before proceeding with the following procedure. Refer to Troubleshooting, "Diagnostic Capabilities - Clearing Active Codes for On Board Diagnostics (OBD)" for more information on clearing "Active" codes.
Table 1
Diagnostic Trouble Codes    
CDL Code     J1939 Codes     Code Description
(code descriptions may vary)     Comments    
E1154 (1)     3609-17     Low DPF #1 Intake Pressure     The code is logged.    
E1154 (2)     3609-18     Low DPF #1 Intake Pressure     The code is logged.    
Table 2
Troubleshooting Test Steps     Values     Results    
1. Inspect the Exhaust System for Leaks
A. Inspect the exhaust system for leaks between the exhaust manifold and the ARD aftertreatment assembly inlet.
B. Check the exhaust system for loose connections or open ports.
   
Exhaust leaks    
Result: The exhaust system has leaks.
Repair the exhaust. Return the engine to service.
Result: The exhaust system does not have leaks.
Proceed to Test Step 2.
   
2. Inspect the DPF Differential Pressure Lines, Fittings, and Manifold
A. Ensure that the DPF differential pressure lines are securely connected and have no leaks.
B. Ensure that the DPF differential pressure lines, fittings, and manifold are free from obstructions. Make sure that moisture has not frozen in the lines, fittings, and manifold.
   
Obstructions    
Result: The DPF differential pressure lines, fittings, and manifold are securely connected and free from leaks and obstructions.
Proceed to Test Step 3.
Result: The DPF differential pressure lines are not connected or the lines, fittings, and manifold have leaks or obstructions.
Clean, repair, or replace the line. Clear all codes. Perform an ARD Ignition Test.
If the ARD Ignition Test passes, return the engine to service.
If the ARD Ignition Test fails, Proceed to Test Step 3.
   
3. Inspect the Diesel Particulate Filter
A. Inspect the inlet of the DPF. Inspect the DPF for a missing or damaged DPF brick.
   
Damaged DPF brick    
Result: The DPF has a damaged or missing DPF brick.
Replace the damaged DPF or missing DPF brick. Return the engine to service.