OPERATOR AR 4612808 - Caterpillar

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. This situation has occurred 3 times in 180 seconds.
The keyswitch has been on for 2 seconds.
Diagnostic codes 168-xx, 3484-xx, 3556-6, and 5487-xx are not active.
Engine power is derated.
Active regeneration is disabled.    
3473-11     Aftertreatment #1 Failed to Ignite : Other Failure Mode     The ARD has failed to ignite within 0.5 seconds for a regeneration cycle.
The keyswitch has been on for 2 seconds.
Diagnostic codes 168-xx, 3484-xx, 3556-6, and 5487-xx are not active.
Engine power is derated.
Active regeneration is disabled.    
Illustration 1 g03327825
System OperationThe 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) in order 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.Test Step 1. Check for Associated Diagnostic Trouble Codes
Establish communication between the electronic service tool and the engine ECM.
Table 2 lists the diagnostic trouble codes that can be associated with the "3473-xx 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     Associated Diagnostic Procedure    
3484-0     Aftertreatment #1 Ignition : High - most severe (3)     ARD Ignition - Test    
3484-3     Aftertreatment #1 Ignition : Voltage Above Normal     Ignition Keyswitch Circuit And Battery Supply Circuit- Test    
3484-4     Aftertreatment #1 Ignition : Voltage Below Normal     ARD Ignition - Test    
3556-6     Aftertreatment 1 Hydrocarbon Doser 1 :Current Above Normal     Injector Solenoid Circuit - Test    
6581-6     Aftertreatment 1 Hydrocarbon Doser 2 :Current Above Normal     Injector Solenoid Circuit - Test    Results:
An associated diagnostic trouble code is present. - Repair: Refer to Troubleshooting, "Diagnostic Trouble Codes" in order to troubleshoot the associated diagnostic code.STOP
An associated diagnostic trouble code is not present. - Proceed to Test Step 2.Test Step 2. Inspect the ARD Ignition System
Visually inspect the components for the ARD ignition system. Check for the following faults:
Loose connections or damaged connectors
Moisture on the connectors or the wiring
Damage caused by excessive heat
Damage