C13 and C15 On-highway Engines Caterpillar

Table 1 lists the diagnostic codes that relate to the combustion air system.

Illustration 1 shows an overview of the troubleshooting procedure. Follow the steps in order.

Illustration 1	g01999943

Illustration 2	g02000554

Feature on the Caterpillar Electronic Technician (ET) for the Combustion Air System

"Engine Air System Verification Test" - This automated test helps in the troubleshooting of problems with the flow of combustion air. The test is performed while the engine is running. Approximately 2 minutes are required in order for the test to run. Cat ET commands the air pressure control valve to move to various positions during the test. Cat ET measures the value of certain parameters during the test. The test results are displayed on Cat ET. The results must be interpreted in order to determine the troubleshooting that must be performed. Refer to Troubleshooting, "Air System Verification - Test" for additional information on this test.

Test Step 1. Determine The Code

1. Establish communication between the Caterpillar Electronic Technician (ET) and the engine ECM.

   Note: The communications adapter must be communicating on both data links in order to perform this procedure. Refer to Troubleshooting, "Electronic Service Tools" for additional information, if necessary.

2. Look for the following codes:

   • 3487-7

   • 3832-15

   • 3832-17

Results:

• A 3487-7, 3832-15, or 3832-17 code is present. - Proceed to Test Step 2.

• A 3487-7, 3832-15, or 3832-17 code is not present, but there may be a problem with the ARD. - Proceed to Test Step 2.

Test Step 2. Measure the Differential Pressure Across the Diesel Particulate Filter (DPF)

1. Measure the differential pressure across the DPF while the engine is at 1400 rpm.

Results:

• The differential pressure is less than 8.5 kPa (1.2 psi). - Proceed to Test Step 3.

• The differential pressure is greater than 8.5 kPa (1.2 psi). -

  Repair: Clean the Diesel Particulate Filter. Do not reset the ash model.

  Proceed to Test Step 3.

Test Step 3. Perform the "Engine Air System Verification Test"

1. Perform the "Engine Air System Verification Test". Refer to Troubleshooting, "Air System Verification Test" for additional information on the test, if necessary.

   Note: Cat ET Air System Verification Test does not determine if the results are acceptable. Acceptable ranges are provided in the Troubleshooting, "Air System Verification Test".

   Note: High backpressure, due to a plugged DPF from not regenerating, will cause erroneous "Engine Air System Verification Test" results.

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   Table 2

   Procedures for the Results of the "Engine Air System Verification Test" (1)
   	Test Point 3	Test Point 4	Troubleshooting Procedure
   "Boost Pressure"	Within the acceptable range	Within the acceptable range	Procedure "A" and Procedure "C" If procedures "A" and "C" do not correct the problem, replace the air pressure control valve.
   "Aftertreatment 1 Secondary Mass Air Flow"	Within the acceptable range	Below minimum
   "Boost Pressure"	Below minimum	Within the acceptable range	Procedure "B"
   "Aftertreatment 1 Secondary Mass Air Flow"	Above maximum	Within the acceptable range
   "Boost Pressure"	Within the acceptable range	Above maximum	Procedure "B"
   "Aftertreatment 1 Secondary Mass Air Flow"	Within the acceptable range	Below minimum
   "Boost Pressure"	Within the acceptable range	Within the acceptable range	Procedure "C"
   "Aftertreatment 1 Secondary Mass Air Flow"	Above maximum	Above maximum
   "Boost Pressure"	Within the acceptable range	Within the acceptable range	Refer to the "Results" section of this Test Step.
   "Aftertreatment 1 Secondary Mass Air Flow"	Within the acceptable range	Within the acceptable range
   "Boost Pressure"	Below minimum	Below minimum	Inspect for intake leaks. Test points one and two will probably be at the minimum or below the minimum.

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   (1)	Refer to Troubleshooting, "Air System Verification Test" for the acceptable results for the test.

2. Refer to Table 2. Determine the appropriate procedure according to the results of the "Engine Air System Verification Test".

   For example, the results of the test indicate the following conditions:

   • The "Boost Pressure" was within the acceptable range during Test Point 3 and Test Point 4.

   • The "Aftertreatment 1 Secondary Mass Air Flow" was above the acceptable range during Test Point 3 and above the acceptable range during Test Point 4.

   In this example, Procedure "C" applies.

Expected Result:

The results are not within the acceptable range. The appropriate procedure was identified.

Results:

• The results are not within the acceptable range. The appropriate procedure was identified. - Perform the appropriate procedure.

• The results are within the acceptable range. - Proceed to Test Step 6.

Test Step 4. Procedure "A"

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Illustration 3	g01435315
Inspection points for the line between the air pressure control valve and the venturi A typical configuration is shown.

1. Refer to Illustration 3. Inspect the line between the air pressure control valve and the venturi. Look for these problems: cracked lines and loose hardware. Make the necessary repairs.

2. Run the "Engine Air System Verification Test" again.

Expected Result:

The results for Test Point 3 and Test Point 4 are within the acceptable range.

Results:

• The results for Test Point 3 and Test Point 4 are within the acceptable range. - Proceed to Test Step 7.

• The results for Test Point 3 and Test Point 4 are not within the acceptable range. - Proceed to Test Step 6.

Test Step 5. Procedure "B"

1. Replace the air pressure control valve.

2. Run the "Engine Air System Verification Test" again.

Expected Result:

The results for Test Point 3 and Test Point 4 are within the acceptable range.

Results:

• The results for Test Point 3 and Test Point 4 are within the acceptable range. - Proceed to Test Step 7.

Test Step 6. Procedure "C"

Note: A small leak in the combustion air system can cause problems. Carefully inspect the combustion air system. Arrows in the illustrations indicate the inspection points.

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Illustration 4	g01435018
Inspection points for the tubing between the venturi and the sensor A typical configuration is shown.

1. Refer to Illustration 4. Carefully inspect the tubing between the venturi and the sensor by using the following procedure:

   1. Remove the flexible hoses. Inspect the flexible hoses. Look for these problems: holes, cuts and other damage.

   2. Verify that all of the worm drive band type clamps are tight.

   3. Verify that all of the line nuts on the venturi are tight.

2. If no problems are found, remove the differential pressure sensor from the engine.
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   Illustration 5	g01409818
   Fillets on the hose barb couplers

3. Refer to Illustration 5. Inspect the fillets at the base of the hose barb couplers. Look for cracks.

   If there are cracks, replace the sensor.

   If there are no cracks, install the sensor.

4. Verify that the four clamps for the flexible hoses for the differential pressure sensor are tight. The flexible hoses must not slip on the hose barb couplers. The flexible hoses must not slip on the tubing.

5. Run the "Engine Air System Verification Test" again.

Expected Result:

The results for Test Point 3 and Test Point 4 are within the acceptable range.

Results:

• The results for Test Point 3 and Test Point 4 are within the acceptable range. - Proceed to Test Step 7.

• The results for Test Point 3 and Test Point 4 are not within the acceptable range. -

  Repair: Replace the air valve.

  Proceed to Test Step 7.

Test Step 7. Data Log Stationary Regeneration

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

1. 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 1 hour.

2. 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"

3. 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 DPF. 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.

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

Results:

• New diagnostic codes are logged. -

  Repair: Troubleshoot the diagnostic codes.

  STOP

• The regeneration completed successfully. -

  Repair: Interpret the data log in order to determine if the problem has been resolved. Contact your local Caterpillar Technical Communicator for further assistance.

  STOP