C4.4 and C6.6 Engines Caterpillar

Diesel Particulate Filter Collects Excessive Soot

Usage:

C4.4 448

If the soot load becomes excessive, the ECM activates the applicable code.

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Table 1
Diagnostic Trouble Codes for Excessive Soot Load
J1939 Code	CDL Code	Code Description (code descriptions may vary)	Comments
3719-16	E995 (2)	High Diesel Particulate Filter #1 Soot Loading - Level 2	The estimated soot load is above 116 percent. Engine power is gradually derated as the soot load increases. The emissions system failure lamp will flash.
3719-0	E995 (3)	High Diesel Particulate Filter #1 Soot Loading - Level 3	The estimated soot load is above 127 percent. Engine power is derated 100 percent. The emissions system failure lamp will flash and a warning horn will sound.
5629-31	E1265 (1)	DPF Active Regeneration Inhibited Due to Low Exhaust Gas Pressure	The exhaust gas pressure is too low to support DPF regeneration.

The Electronic Control Module (ECM) uses the soot sensors to monitor the soot load in the Diesel Particulate Filter (DPF). An excessive accumulation of soot in the DPF can be caused by the following faults:

Faulty soot sensor system
Oil in the exhaust system
Faulty injectors
A mechanical fault in a cylinder
Low exhaust gas pressure
A faulty exhaust back pressure regulator
A fault in the NOx Reduction System (NRS)
Fuel with a high sulfur content

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Table 2
Required Tools
Tool	Part Number	Part Description	Qty
A	366-7782	Attenuator	1

Engine operation must be kept to a minimum to minimize the amount of soot that is created. Follow the troubleshooting procedure to minimize the amount of engine operation.

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Table 3
Troubleshooting Test Steps	Values	Results
1. Check for Active Diagnostic Trouble Codes A. Turn the keyswitch to the ON position. B. Connect the electronic service tool. Check for active diagnostic trouble codes.		Result: A 3719 (E995) code is active. Proceed to Test Step 2. Result: A 5629-31 (E1265) code is active. Proceed to Test Step 6. Result: A code other than the codes listed in Table 1 is active. Repair: Diagnose and rectify the fault before continuing with this procedure. Refer to Troubleshooting, "Diagnostic Trouble Codes".
2. Visually Inspect the Soot Sensor System A. Inspect the coaxial cables between the soot sensor and the antennas for damage. B. Make sure that the antenna connectors are correctly tightened to 1.2 N·m (10.6 lb in).	Soot sensor	Result: The soot sensor cables are damaged. Repair: Replace the soot sensor. Proceed to Test Step 3. Result: Other corrective actions were performed. Start the engine and then use the electronic service tool to perform the "Aftertreatment Regeneration System Test". Stop the engine and then check for a 3719 (E995) code. If the 3719 (E995) code has been eliminated, proceed to Test Step 9. If the 3719 (E995) code is still present, proceed to Test Step 3. Result: No corrective actions were performed. Proceed to Test Step 3.
3. Test the Soot Sensor System A. Disconnect the soot antenna connectors and install Tooling A. B. Perform the "DPF Soot Loading Sensor Functional Test" on the electronic service tool by selecting the following menus: · "Diagnostics" · "Diagnostic Tests" · "DPF Soot Loading Sensor Functional Test" C. Disconnect the coaxial cables from the attenuator.	Soot sensor	Result: The "DPF Soot Loading Sensor Functional Test" fails. Repair: Replace the soot sensor. Use the electronic service tool to perform the "Aftertreatment Regeneration System Test". If necessary, diagnose any reported fault codes and then proceed to Test Step 9. Result: The "DPF Soot Loading Sensor Functional Test" is successful. Proceed to Test Step 4.
4. Check for Oil in the Exhaust System A. Remove the flexible exhaust pipe. Refer to Disassembly and Assembly, "Flexible Exhaust Pipe - Remove and Install". B. Inspect the exhaust system and Clean Emissions Module (CEM) inlet for oil deposits.	Exhaust system	Result: Oil deposits are present in the exhaust system. Repair:Refer to Troubleshooting, "Exhaust System Contains Oil". Result: No oil deposits are found in the exhaust system. Proceed to Test Step 5.
5. Check for Engine Faults A. Start the engine. B. Use the electronic service tool to perform the "Cylinder Cutout Test".	Engine	Result: The "Cylinder Cutout Test" fails. Repair: Investigate the cause of the fault and rectify. If necessary, contact the Dealer Solutions Network (DSN). Result: The "Cylinder Cutout Test" is successful. Proceed to Test Step 6.
6. Investigate Cause of 5629-31 (E1265) Code Note: Diagnostic code 5629-31 (E1265) indicates that the exhaust gas pressure is too low to promote DPF regeneration. A. Check the exhaust system from the engine to the CEM for gas leaks. B. Check the sensors on the CEM for signs of gas leaks. C. Check that the exhaust system insulation is correctly installed.	Diagnostic code	Result: Exhaust gas leaks are found in the exhaust system or the CEM. Repair: Rectify the gas leak or make sure that the CEM sensors are correctly installed. Proceed to Test Step 9. Result: Exhaust system insulation is missing or damaged. Repair: Repair the exhaust system insulation. Proceed to Test Step 9. Result: There are no exhaust gas leaks and the insulation is OK. Proceed to Test Step 7.
7. Check the Exhaust Back Pressure Regulator and the NRS system A. Use the Electronic service tool to check for diagnostic codes that are associated with the Exhaust Back Pressure Regulator (EBPR) or the NRS system.	EBPR and NRS systems	Result: A diagnostic code is present that is associated with the EBPR or the NRS system. Repair: Refer to Troubleshooting, "Diagnostic Trouble Codes"for information on troubleshooting the code. Result: There are no diagnostic codes present for the EBPR or the NRS system. Proceed to Test Step 8.
8. Check for High Sulfur Fuel A. Ensure that the correct specification of fuel is being used. Refer to the Operation and Maintenance Manual for the correct specification. Note: If fuel with a high sulfur content is used, this fault will reoccur and a replacement CEM may be required.	Fuel	Result: High sulfur fuel is in use. Repair: Drain the fuel tank, flush the fuel lines, and replace the fuel filters. Refill the fuel system with fuel of the correct specification. Start the engine and use the electronic service tool to perform the "Aftertreatment Sulfation Recovery Procedure". Result: The fuel is the correct specification. Contact the Dealer Solutions Network (DSN).
9. Prepare the Unit for Service A. Start the engine and use the electronic service tool to perform the "Manual Diesel Particulate Filter Regeneration."	DPF	Result: The soot content of the DPF returns to normal. Return the unit to service. Result: The soot content of the DPF remains high. Contact the Dealer Solutions Network (DSN).