C7 and C9 On-Highway Engines Caterpillar

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

The Engine Control Module (ECM) maintains an estimate of the soot load in the DPF. The estimate is based on the engines operating conditions. If the ECM estimates that the soot load is excessive, the ECM activates the applicable code.

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

1. 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.

2. Verify ARD Disable Switch is not Disabling Regens

   If 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.

3. Check for Associated Diagnostic Trouble Codes

   Troubleshoot 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 faults

   Troubleshoot 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

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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)

4. Determine the Type of Cleaning System for the Nozzles Inside the ARD Combustion Head

   Determine 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.

   STOP

   Results:

   An electric heating element is used to clean the nozzles.

   Proceed to Step 5.

5. Determine DPF Differential Pressure

   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.

   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.

6. 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.

7. Inspect the DPF

   Perform 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.

   1. 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 the ARD.

      Perform a manual cylinder cutout test. Manually cut out each cylinder while the exhaust is monitored. Look for the smoke to disappear as each cylinder is cut out. Replace any injectors that cause the engine to smoke and run rough when the cylinder is not cut out. Clean the inside of the inlet section of the DPF and the front face of the DPF. Assemble the DPF. Run the engine at 1400 rpm for 15 minutes.

      Set the value of the "Data Link ARD Disable Status" configuration parameter to "Not Disabled" in order to enable the ARD. Proceed to Test Step 8.

8. Datalog a Stationary Regeneration

   Refer to Special Instruction, REHS3407, "Using the Caterpillar Electronic Technician (ET) Data Log" for information on using the data log.

   1. Clear all active diagnostic and active event codes before starting the regeneration.

   2. Configure the settings on the "General" tab according to the following information:

      Sample Rate - Enter a sample rate of 20 samples per minute.

      Duration - Enter a duration of one hour.

   3. The data log must capture the following parameters. Create a group that contains only the following parameters, if necessary:
      • ARD Inlet Temperature

      • ARD Flame Temperature

      • ARD Outlet Temperature

      • Diesel Particulate Trap #1 Intake Temperature

      • Diesel Particulate Trap #1 Outlet Temperature

      • Diesel Particulate Trap #1 Differential Pressure

      • ARD Pilot Fuel Pressure

      • ARD Fuel Pressure

      • ARD Fuel Pressure Control Command Percentage

      • ARD Air Pressure Control Command Percentage

      • ARD Secondary Air Gas Mass Flow

      • CGI Mass Flow Rate

      • Boost Pressure

      • Engine Speed

   4. Start the data log. Then, begin a stationary regeneration by selecting the following menu items on Cat ET:
      • "Service"

      • "Service Procedures"

      • "Manual Diesel Particulate Filter Regeneration"

      Cat ET will display a "Waiting On Requirements" window. The ECM will automatically elevate the engine speed to 1400 rpm. If the "Waiting On Requirements" window remains displayed for more than 5 minutes, abort the regeneration. Then, select the menu options again in order to start the stationary regeneration.

      The duration of the stationary regeneration depends on the soot load in the Diesel Particulate Filter. The ECM will automatically return the engine speed to low idle after the stationary regeneration is complete.

      Note: The ECM tests the nozzles for plugging after the stationary regeneration is complete. Approximately 10 minutes are required in order for the test to provide a result. A code will become active if the nozzles are plugged.

   5. Stop the data log after the engine speed returns to idle.

      Results:

      A 310 diagnostic code is returned at the end of the stationary regeneration and the parameters fall within the ranges of Table 2. Contact your Technical Communicator.

      Results:

      A 310 diagnostic code is returned at the end of the stationary regeneration and the parameters do not fall within the ranges of Table 2. Troubleshoot per Table 2.

      Results:

      A 310 diagnostic code is not activated at the end of the stationary regeneration. Troubleshoot the returned ET fault code.

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      Table 2

      Parameter	Target Conditions	Action
      DPF #1 Intake Temperature	Target is 583° C (1083° F), in cold conditions some CRS housings may not achieve the full 583° C (1083° F). Temperatures greater than 551° C (1025° F) should occur in all climates	Low Temperature: Refer to Troubleshooting Guide, "ARD Temperature Is Low" High Temperature: Cat ET will return fault code. Troubleshoot code. No interpretation necessary.
      DPF #1 Outlet Temperature	Outlet temperature will lag inlet temperature during the warm-up period. DPF outlet should be ±40° F of inlet by end of the 583° C (1083° F) hold.	Low Temperature: Refer to Troubleshooting Guide, "Diesel Particulate Filter Temperature Is Low" High Temperature: Refer to Troubleshooting Guide, "Diesel Particulate Filter Temperature Is High"
      ARD Pilot Fuel Pressure	When ARD Fuel Pressure Control Command Percentage is 55% or greater, pilot pressure should be in range of 1475 kPa (214 psi) to 1975 kPa (288 psi)	Low Pressure: Refer to Troubleshooting Guide, "Fuel System Pressure - Test" High Pressure: Refer to Troubleshooting Guide, "ARD Fuel Pressure Is High"
      ARD Fuel Pressure	The amount of ARD Fuel Pressure required to achieve the desired DPF Intake Temperature is a function of Engine bore size, exhaust piping, DPF configuration, and environmental conditions such as temperature and altitude. A typical C9 at standard conditions will range in ARD fuel pressure from 0 kPa (0 PSI) to 48 kPa (7 psi) to achieve 583° C (1081° F).	Low Pressure: Refer to Troubleshooting Guide, "Fuel System Pressure - Test" High Pressure: Refer to Troubleshooting Guide, "ARD Fuel Pressure Is High"
      CGI Mass Flow Rate	Some CGI Mass Flow Rate leakage through the CGI valve is typical during a forced regeneration. If CGI Mass Flow Rate is questionable perform an Air System Verification test.	Refer to Troubleshooting Guide, "Clean Gas Induction - Test"
      Flame Temperature	Flame temperature will vary greatly based on A/F ratio, environmental conditions, and CRS head.	Too Low: A 112F error code will be returned. Refer to Troubleshooting Guide, "ARD Combustion - Test" Too High: If above 1205° C (2200° F), remove, clean, and inspect. Replace if damaged.