C7.1 Engines and Generator Sets Caterpillar

ARD Loss of Combustion

Usage:

C7.1 770

Table 1 lists the diagnostic code that relates to the combustion air system.

Note: Some of the following codes may not be applicable for certain applications.

Note: Refer to Troubleshooting, "Service Tool Features" for information about service features.

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Table 1
Diagnostic Trouble Codes
J1939 Code	CDL Code	Description	Comments
3474-14	E1026 (1)	Aftertreatment #1 Loss of Combustion	The Aftertreatment Regeneration Device (ARD) has stopped generating heat at least four times during active high-speed regeneration. Associated codes may indicate the system that caused the loss of combustion to occur. The code must be cleared with the "Reset All" button on the active diagnostics screen in the electronic service tool. If active regeneration is initiated with the operator forced regeneration switch, the Engine Control Module (ECM) clears this code automatically.
3474-31	E1026 (2)	Aftertreatment #1 Loss of Combustion	The ARD has stopped generating heat at least four times during active regeneration. Associated codes may indicate the system that caused the loss of combustion to occur. The code must be cleared with the "Reset All" button on the active diagnostics screen in the electronic service tool. If active regeneration is initiated with the operator forced regeneration switch, the ECM clears this code automatically.

System Operation

The combustion air system routes pressurized air from the outlet of the turbocharger compressor to the ARD. The combustion air is mixed with fuel inside the ARD. The air/fuel mixture is ignited and the air/fuel mixture is burned to provide heat for the diesel particulate filter.

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Illustration 1	g06127114
Overview for the ARD combustion head (1) Flame detection temperature sensor (2) Electrical connection for the ARD nozzle heater (3) ARD combustion head (4) ARD pilot filter connector (5) ARD spark plug (6) Inlet for the combustion air

When the ECM determines that the combustion air valve should be opened, the controller sends a pulse width modulated (PWM) signal to the valve. This PWM signal causes the valve to open. A position sensor located in the combustion air valve assembly then sends a signal back to the ECM showing the actual position of the valve.

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Table 2
Associated Diagnostic Trouble Codes
J1939 Code	CDL Code
102-18	E1045
3480-15 or 3480-16	E1050
3480-17 or 3480-18	E1052
3487-7	E1041 (1)

Complete the procedure in the order in which the steps are listed.

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Table 3
Troubleshooting Test Steps	Values	Results
1. Check for Associated Diagnostic Trouble Codes A. Establish communication between the electronic service tool and the Electronic Control Module (ECM). Refer to Troubleshooting, "Electronic Service Tools", if necessary. B. If troubleshooting a E1026 or a 3474 code, access the "Aftertreatment Regeneration History" in the electronic service tool. Click the information tab, then click History, and then click Aftertreatment Regeneration History. If there were three successful regenerations since the code was logged, do not troubleshoot this code. Clear the code and return the unit to service. Table 2 lists the diagnostic trouble codes that are associated with an E1026 code. Determine if any of the codes in Table 2 are present.	Diagnostic Code	Result: An associated diagnostic trouble code is not present. Proceed to Test Step 2. Result: An associated diagnostic trouble code is present. Repair: Refer to Troubleshooting, "Diagnostic Trouble Codes" or Troubleshooting, "Event Codes"to troubleshoot the associated diagnostic code.
2. Check the Current Flow Through the Heater A. Verify that the engine is off. Use a clamp-on ammeter to check the current flow through the heater.	Between 7.0 A and 14 A for a 12 V system. Or, between 3.5 A and 7 A for a 24 V system	Result: The current flow is OK. Proceed to Test Step 3. Result: The current flow is not between 7.0 A and 14 A for a 12 V system. The current flow is not between 3.5 A and 7 A for a 24 V system. Repair: There may be a problem with the ARD nozzle. Refer to Troubleshooting, "ARD Nozzle Heater - Test".
3. Perform the "ARD Air System Service Test" A. Reset all active codes and clear all logged codes. Use the electronic service tool to perform an "ARD Air System Service Test" to verify that the problem is resolved.	ARD Air System Service Test	Result: The "ARD Air System Service Test" failed. Repair: There is a problem with the ARD combustion air system. Refer to Troubleshooting, "ARD Combustion Air - Test". Result: The "ARD Air System Service Test" passed. Proceed to Test Step 4.
4. Clean the Flame Detection Temperature Sensor A. Remove flame detection temperature sensor (1). B. Clean the flame detection temperature sensor. Use a nonmetallic cleaning pad to clean the sensor.	Flame Detection Temperature Sensor	Result: The components are clean. The flame detection temperature sensor is not damaged. Repair: Install the flame detection sensor. Proceed to Test Step 5. Result: The flame detection temperature is damaged. Repair: Replace flame detection temperature sensor. Proceed to Test Step 5.
5. Check the ARD for Proper Operation A. Reset all active codes and clear all logged codes. Use the electronic service tool to perform an "ARD Ignition Test" to verify that the problem is resolved. The ARD Ignition Test cannot be performed if the DPF soot loading is above 80%. When the DPF soot loading is above 80%, the Manual DPF Regeneration must be performed using the electronic service tool.	ARD Ignition Test	Result: The test is successful. Proceed to Test Step 8. Result: The test is not successful. Proceed to Test Step 6.
6. Replace the Fitting that Contains the Filter in the ARD Head A. Replace fitting (4) that contains the filter in the ARD head. B. Reset all active codes and clear all logged codes by using the electronic service tool. C. Perform the "ARD Ignition Test" using the electronic service tool. Refer to System Operation and Testing and Adjusting, "ARD Fuel System - Test". The ARD Ignition Test cannot be performed if the DPF soot loading is above 80%. When the DPF soot loading is above 80%, the Manual DPF Regeneration must be performed using the electronic service tool.	Filter Fittings	Result: The "ARD Ignition Test" was successful and no codes were logged. Proceed to Test Step 8. Result: The "ARD Ignition Test" was not successful. Proceed to Test Step 7.

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Illustration 2	g06127137
(7) Fouled slot

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Illustration 3	g06127151
(8) Acceptable soot accumulation

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Table 4
Troubleshooting Test Steps	Values	Results
7. Inspect ARD Swirl Plate A. Remove ARD head (3). Refer to Disassembly and Assembly, "Combustion Head Group (ARD) - Remove and Install - Clean Emissions Module" for the proper procedure to remove the ARD combustion head. Soot accumulation is normal. Slot fouling is defined as more than 1/2 the inner row slots being completely blocked. Partially blocked inner row slots are normal and do not affect regeneration performance. Refer to Illustrations 2 and 3 to verify if the swirl plate is fouled. B. Inspect the swirl plate for fouled slots. Refer to Illustrations 2 and 3 to verify if the swirl plate is fouled.	Swirl Plate	Result: The swirl plate is fouled. Repair: Clean the swirl plate. Refer to Testing and Adjusting, "Swirl Plate (ARD Combustion) - Inspect/Clean". Reset all active codes and clear all logged codes. Perform the "ARD Ignition Test" in the electronic service tool and verify that there are no fuel leaks. The ARD Ignition Test cannot be performed if the DPF soot loading is above 80%. When the DPF soot loading is above 80%, the Manual DPF Regeneration must be performed using the electronic service tool. Proceed to Test Step 8. Result: The swirl plate is not fouled. Repair: Replace the ARD combustion head. Refer to Disassembly and Assembly, "Combustion Head - Remove and Install". Reset all active codes and clear all logged codes. Perform the "ARD Ignition Test" in the electronic service tool and verify that there are no fuel leaks. The ARD Ignition Test cannot be performed if the DPF soot loading is above 80%. When the DPF soot loading is above 80%, the Manual DPF Regeneration must be performed using the electronic service tool. Proceed to Test Step 8.
8. Perform a "Manual DPF Regeneration" This test must be performed through the electronic service tool. The electronic service tool enhances the diagnostics during the service test. A. Clear all diagnostic codes using the electronic service tool. B. Start the engine. Allow the engine to idle for 3 minutes. Do not use the operators switch for a stationary DPF regeneration. The service tests provide enhanced diagnostics that are necessary for proper troubleshooting and repair. C. Start a "Manual DPF Regeneration" in the electronic service tool.	Manual DPF Regeneration	Result: The "Manual DPF Regeneration" completed successfully. There are no additional codes. Return the unit to service. Result: The "Manual DPF Regeneration" did not complete successfully. There are additional codes. Repair: Troubleshoot the additional codes before returning the unit to service. Refer to Troubleshooting for the correct procedure. Verify that the problem is resolved.