C1.5 and C2.2 Engines for Caterpillar Built Machines Caterpillar

Note: Before commencing this procedure, ensure that the rework instructions detailed in M0083779, "Aftertreatment Regeneration on Certain C1.5 and C2.2 Engines" has been carried out on the engine.

Use this procedure to troubleshoot the following code:

Table 1

Diagnostic Trouble Codes for ARD Failed to Ignite
J1939 Code	Code Description	Comments
3473-7	Aftertreatment #1 Failed to Ignite : Not Responding Properly	The ARD temperature has failed to increase as expected. The keyswitch has been ON for 2 seconds. Diagnostic codes 168-xx, 3484-xx, 3556-6, and 5487-xx are not active. Active regeneration is disabled.
3473-11	Aftertreatment #1 Failed to Ignite : Other Failure Mode	The keyswitch has been ON for 2 seconds. Diagnostic codes 168-xx, 3484-xx, 3556-6, and 5487-xx are not active. Active regeneration is disabled.
3473-12	Aftertreatment #1 Failed to Ignite : Failure	The ARD has failed to ignite for a regeneration cycle or the ARD failed to ignite during an ARD Ignition Test. Usually, this code is accompanied by another logged code that indicates the condition that caused the failure to ignite.

Illustration 1	g03773198
(1) Air compressor (2) Compressor intake hose (3) Compressor outlet hose (4) Reed valve (5) ARD air intake tube (6) ARD (7) ARD glow plug

System Operation

The combustion air system routes pressurized air from the outlet of air compressor (1) to the ARD. Reed valve (4) between hose assembly (3) and tube assembly (5) prevents exhaust gas flowing towards the air compressor. The combustion air is mixed with fuel inside ARD combustion chamber (6). The air/fuel mixture is ignited by glow plug (7) to increase the temperature of the exhaust gas. The high temperature exhaust gas burns off the soot in the Diesel Particulate Filter (DPF). This process is known as DPF regeneration.

The ECM controls the operation of an electronic clutch in the air compressor. The ECM also controls the fuel injectors in the ARD.

The ECM controls the ARD glow plug. Whenever the ARD is required to operate, the ECM provides power to the glow plug through a voltage dropper.

If the amount of fuel or air that enters the ARD is incorrect or the glow plug does not operate correctly, combustion may not occur.

Associated Diagnostic Trouble Codes

Use the following procedure to check for associated diagnostic codes:

1. Establish communication between the electronic service tool and the engine ECM.

2. Table 2 lists the diagnostic trouble codes that can be associated with the "3473-7 Aftertreatment #1 Failed to Ignite" code. Determine if any of the codes in Table 2 are present.

Table 2

Associated Diagnostic Codes
J1939 Code	Description	Actions Required
1485–14	ECM Main Relay : Special Instruction	This code is most likely caused by shutting down the engine using the battery disconnect switch instead of the keyswitch for three consecutive shutdowns or using the battery disconnect switch immediately after the keyswitch has been turned OFF. An "ARD Failed to Ignite" condition after this code has been active may indicate damage to the ARD fuel injectors. Perform Test Step 11 and Test Step 12 of "ARD Fuel Supply" in this procedure to test the ARD fuel injectors. If the ARD fuel injectors are not injecting fuel, replace the ARD fuel injectors. Refer to Disassembly and Assembly, Fuel Injector - Remove and Install (Aftertreatment Regeneration Device (ARD) Primary Fuel Injector) and Disassembly and Assembly, Fuel Injector - Remove and Install (Aftertreatment Regeneration Device (ARD) Secondary Fuel Injector). If the "ARD Failed to Ignite" condition still exists, continue with this procedure from the beginning.
3484-0	Aftertreatment #1 Ignition : High - most severe (3)	Refer to ARD Ignition - Test.
3484-3	Aftertreatment #1 Ignition : Voltage Above Normal	Refer to Ignition Keyswitch Circuit And Battery Supply Circuit- Test.
3484-4	Aftertreatment #1 Ignition : Voltage Below Normal	Refer to ARD Ignition - Test
3556-6	Aftertreatment Fuel Injector #1: Current Above Normal	Refer to ARD Nozzle - Test.
6581-6	Aftertreatment #1 Hydrocarbon Doser #2 : Current Above Normal	Refer to ARD Nozzle - Test.
3719-0	DPF #1 Soot Loading Percent : High - most severe (3)	Refer to Diesel Particulate Filter Collects Excessive Soot
5487-3	Aftertreatment #1 Burner Unit Combustion Chamber Temperature : Voltage Above Normal	Refer to Engine Temperature Sensor Open or Short Circuit - Test (Active Sensors).
5487-4	Aftertreatment #1 Burner Unit Combustion Chamber Temperature : Voltage Below Normal	Refer to Engine Temperature Sensor Open or Short Circuit - Test (Active Sensors).
4765-3	Aftertreatment DOC Intake Gas Temperature: Voltage Above Normal	Refer to Engine Temperature Sensor Open or Short Circuit - Test (Active Sensors).
4765-4	Aftertreatment DOC Intake Gas Temperature: Voltage Below Normal	Refer to Engine Temperature Sensor Open or Short Circuit - Test (Active Sensors)

If the associated diagnostic trouble code is present, refer to Troubleshooting, “Diagnostic Trouble Codes” to troubleshoot the associated diagnostic code.

ARD Ignition System

Visually inspect the components for the ARD ignition system. Check for the following faults:

1. Confirm that the ARD glow plug wiring is connected to the correct relay and correct pins on ECM. Refer to the appropriate Electrical Schematic.

2. Confirm that the ARD glow plug wiring is not damaged which can cause a short circuit.

3. Confirm that the Alternator is charging.

4. Confirm that the Alternator regulator has not failed and the battery voltage is less than 14.5V.

5. Confirm that the ARD glow plug fuse has not blown.

6. Ensure that the ARD glow plug tightening torque in the ARD head is 23 N·m (17 lb ft).

7. Ensure that the ARD glow plug nut tightening torque is 1.5 N·m (1.1 lb ft).

8. Use electronic service tool to override the ARD glow plug and check that the voltage drop over the dropping resistor is 2V.

9. Use electronic service tool to override the ARD glow plug and check that the glow plug relay is operating correctly.

10. Use electronic service tool to override the ARD glow plug and check that the glow plug heats up (should visibly glow).

ARD Air Supply

Visually inspect the components for the ARD Air supply. Check for the following faults:

1. Confirm that the ARD Air pump wiring is connected to the correct relay and correct pins on ECM. Refer to the appropriate Electrical Schematic.

2. Confirm that the ARD Air pump fuse has not blown.

3. Confirm that there are no kinks in the air lines to restrict the flow.

4. Confirm that the reed valve is not blocked and can move freely.

5. Confirm that the air pump belt is tensioned correctly: New belt = 310 N (70 lb), Used belt = 220 N (49.5 lb). If the air pump belt is damaged or worn, replace the belt.

6. Confirm that the ARD air pump wiring is not damaged.

7. Check if the air filter is blocked. Change filter if maintenance schedule has passed. Refer to the Operation and Maintenance Manual, "Maintenance Interval Schedule".

8. Use electronic service tool to override the ARD Air pump and check that the ARD Air Pump relay is operating correctly.

9. Use electronic service tool to override the ARD Air pump and check that the ARD Air Pump clutch activates.

ARD Fuel Supply

Visually inspect the components for the ARD Fuel supply. Check for the following faults:

1. Confirm that the ARD injector wiring is connected to the correct relay and correct pins on ECM. Refer to the appropriate Electrical Schematic.

2. Confirm that the engine wiring harness is connected to the correct ARD injector (Injector 1 = brown connector, Injector 2 = gray connector).

3. Confirm that the ARD injector fuse has not blown.

4. Confirm if the electric lift pump is damaged.

5. Confirm that there are no kinks in the fuel lines to restrict the flow.

6. Check if the primary fuel filter is blocked. Change filter if maintenance schedule has passed. Refer to the Operation and Maintenance Manual, "Maintenance Interval Schedule".

7. Check if the secondary fuel filter is blocked. Change filter if maintenance schedule has passed. Refer to the Operation and Maintenance Manual, "Maintenance Interval Schedule".

8. Confirm that there is no air in the fuel line. Allow the lift pump to circulate fuel around the engine at Key on before cranking the engine.

9. Confirm that the battery voltage is greater than 13V during a DPF regeneration.

10. Use electronic service tool to override the ARD injector and check that the ARD injector relay is operating correctly.

11. Use electronic service tool to override the ARD injector 1 and check that ARD injector 1 is injecting fuel.

12. Use electronic service tool to override the ARD injector 2 and check that ARD injector 2 is injecting fuel.

Battery Voltage

1. Confirm that the battery voltage is greater than 13V during a DPF regeneration with all the engine auxiliary components activated.

Aftertreatment Temperature Sensors (3473-12 only)

Visually inspect the Aftertreatment Temperature Sensors component.

1. Confirm that the Aftertreatment temperature sensors are located in the correct position: DOC In (gray), DPF In (black) and DPF Out (white connector).