0322956 JOHNSON ORIFICE, Idle air bleed, No.28

Table 1
Diagnostic Trouble Codes for Excessive Soot Load    
J1939 Code    Description    Information that Relates to the Code    
3719-16     Diesel Particulate Filter #1 Soot Load Percent : High - Moderate Severity (2)     The estimated soot load is high. The ECM shuts down the engine when this code becomes active for the first time. The engine can be started and operated. Engine power is gradually derated as the soot load increases.    
3719-0     Diesel Particulate Filter #1 Soot Load Percent : High - Most Severe (3)     The estimated soot load is very high. Engine operation is limited to 60 second intervals when the Caterpillar Electronic Technician (ET) is not communicating with the ECM.    
3715-31     Diesel Particulate Filter Active Regeneration Inhibited Due to Permanent System Lockout     The estimated soot load is very high. The engine may not operate properly. Factory passwords are required in order to clear this code.    
Follow the troubleshooting procedure in order to determine the root cause of the problem.    Illustration 1 and Illustration 2 show an overview of the troubleshooting procedure. Follow the steps in order.
Illustration 1 g02751679
Illustration 2 g02751681
Troubleshooting Procedure
Determine if DPF Differential Pressure Requires Replacement of DPF.Perform this Step only if you are troubleshooting a 3715-31 code. Otherwise, proceed to Step 2.Use the Caterpillar Electronic Technician (ET) to view the differential pressure across the DPF. If there are two filters, view the differential pressure across both of the filters. The differential pressure is indicated by the following parameters:
"Diesel Particulate Trap #1 Differential Pressure"
"Diesel Particulate Trap #2 Differential Pressure"You may need to create a new group in order to view these parameters.Start the engine. Increase the engine speed to 1400 rpm. Monitor the differential pressure for 30 seconds. Stop the engine.Results:The differential pressure exceeds 15.0 kPa (2.1 psi).Repair:Replace with the appropriate DPF. Use factory passwords in order to clear the 3715-31 code. Return the vehicle to service.Results:The differential pressure is less than 15.0 kPa (2.1 psi).Repair:Do not replace the DPF. Use factory passwords in order to clear the 3715-31 code. Continue to Step 2.
Verify ARD Disable Switch is not Disabling RegensIf the vehicle is equipped with an ARD disable switch, verify that the switch is not disabling the Aftertreatment Regeneration Device (ARD). Refer to the vehicles service manual in order to determine the proper operation of the switch.Proceed to Step 3.
Check for Associated Diagnostic Trouble CodesTroubleshoot any diagnostic codes that relate to the following systems or conditions:
Low boost/ air system faults
ARD
Clean Gas Induction System (CGI)
Injector/ fuel system faultsTroubleshoot the systems in the order that is listed above if there are diagnostic codes for more than one of the systems.Proceed to Step 4
Illustration 3 g02751836
Typical ARD combustion head (1) Electrical connector for the heated nozzle (ARD combustion head with a heated nozzle) (2) Air line for the pressurized air (ARD combustion head that uses pressurized air for cleaning the nozzles)
Determine the Type of Cleaning System for the Nozzles Inside the ARD Combustion HeadDetermine the type of cleaning system for the nozzles inside the ARD combustion head.Results:The ARD purge air system is used to clean the nozzles.Repair:Contact your local Caterpillar Technical Communicator for information on updating the system.STOPResults:An electric heating element is used to clean the nozzles.Proceed to Step 5.
Determine DPF Differential PressureUse the Caterpillar Electronic Technician (ET) to view the differential pressure across the DPF. If there are two filters, view the differential pressure across both of the filters. The differential pressure is indicated by the following parameters:
"Diesel Particulate Trap #1 Differential Pressure"
"Diesel Particulate Trap #2 Differential Pressure"You may need to create a new group in order to view these parameters.Start the engine. Increase the engine speed to 1400 rpm. Monitor the differential pressure for 30 seconds. Stop the engine.If the differential pressure exceeds 15.0 kPa (2.1 psi), run a regen attempt to lower differential pressure.If a regen cannot be completed, do the following steps:
"Nozzle Heater Current Test"
Remove and clean ARD Flame Temperature sensor.
Perform a nozzle heater cycle override.
After performing above steps repeat up to two more regen attempts.Results:The differential pressure is less than 15.0 kPa (2.1 psi).Repair:Proceed to Step 6.Results:The differential pressure is greater than 15.0 kPa (2.1 psi).Repair:Replace with the appropriate DPF. Return the vehicle to service.
Perform the "Engine Air System Verification Test"Perform the "Engine Air System Verification Test". Refer to Troubleshooting, "Air System Verification Test" for information on the test, if necessary.Troubleshoot the test results if the test results are unacceptable. Then, proceed to "ARD Combustion Air –Test".Proceed to Step 7 if the results of the "Engine Air System Verification Test" are acceptable.
Inspect the DPFPerform this Test Step if all of the following conditions are true:
The ARD disable switch was not disabling the ARD.
The results of the "Engine Air System Verification Test" are acceptable.
Remove the inlet section from the DPF. Inspect the inside of the inlet section and the front face of the DPF. Look for oil and for excessive soot.The presence of a small amount of soot is a normal condition. Contact your local Technical Communicator for Caterpillar On-highway Truck Engines if you suspect that the amount of soot is excessive. Continue with this procedure after you have received guidance from the Technical Communicator.If oil is found, inspect the outlet of the turbocharger. Contact your local Technical Communicator for Caterpillar On-highway Truck Engines if oil is found. Continue with this procedure after you have received guidance from the Technical Communicator. Clean the oil from the inside of the inlet section of the DPF and the front face of the DPF. Assemble the DPF. Use Cat ET to disable the ARD. Set the value of the "Data Link ARD Disable Status" configuration parameter to "Disabled" in order to disable the ARD. Run the engine at 1400 rpm for 15 minutes. Then, proceed to the next test step.If no oil is found, leave the inlet section disconnected from the DPF. Use Cat ET to disable the ARD. Set the value of the "Data Link ARD Disable Status" configuration parameter to "Disabled" in order to disable