KIT-ENGINE OVERHAUL 4446548 - Caterpillar

Use this procedure to troubleshoot the following code:
Table 1
Diagnostic Trouble Codes for the Cleaning System for the Nozzles
Code Description Comments
3556-7 Aftertreatment #1 Fuel Injector : Not Responding Properly A 3556-7 code can be set because of the improper use of a pressure gauge for test. There is only one approved location for a pressure gauge in the system. Refer to Troubleshooting, "Fuel System Pressure - Test" for the only acceptable location for a test gauge. Remove any gauge in an unapproved location and test for the 3556-7 code before proceeding with this test. If the 3556-7 code does not recur, resume troubleshooting the original problem.
Follow the troubleshooting procedure in order to identify the root cause of the problem. Illustration 1 and Illustration 2 shows an overview of the troubleshooting procedure. Follow the steps in order.
Illustration 1 g02000615
Illustration 2 g02000617Test Step 1. Determine the Type of Cleaning System for the Nozzles Inside the ARD Combustion Head
Illustration 3 g01976876
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)
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 for the heated nozzle.STOP
An electric heating element is used to clean the nozzles. - Proceed to Test Step 2.Test Step 2. Check for Associated Diagnostic Trouble Codes
Establish communication between the Caterpillar Electronic Technician (ET) and the engine ECM.
Table 2 lists the diagnostic trouble codes that are associated with a 3556-7 code. Determine if any of the codes in Table 2 are present.
Table 2
Associated Diagnostic Trouble Codes
Code Description
4301-5 Aftertreatment #1 Fuel Injector #1 Heater Control : Current Below Normal
4301-6 Aftertreatment #1 Fuel Injector #1 Heater Control : Current Above Normal Results:
An associated diagnostic trouble code is not present. - Proceed to Test Step 3.
An associated diagnostic trouble code is present. - Repair: Troubleshoot the associated diagnostic code.STOPTest Step 3. Check the Current Flow Through the Heater
Verify that the engine is off.
Illustration 4 g01978716
Measuring the current flow
(3) Clamp-on ammeter
(4) Wire
(5) Metal part of the electrical connector
Connect the clamp on ammeter (3) around wire (4 ). Make sure that the jaws of the ammeter are away from the metal part of electrical connector (5).
Start the engine. Activate the "ARD Fuel Nozzle Heater Electric Circuit" override.
Observe the current reading on the ammeter.
Disable the override. Stop the engine. Remove