Indirect Fuel Injector Diagnosis

Indirect Fuel Injector Diagnosis

Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle (Diagnostic System Check - Vehicle) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Strategy Based Diagnosis) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Diagnostic Procedure Instructions) provides an overview of each diagnostic category.

Circuit/System Description
The indirect fuel injector is located on the right rear cylinder head. Fuel is supplied to the indirect fuel injector from the low pressure side of the high pressure fuel pump. An outlet tube is connected between the indirect fuel injector outlet and the exhaust down pipe. When the engine control module (ECM) commands the injector ON fuel is sprayed directly into the exhaust system. The fuel ignites in the exhaust and produces the heat required for the exhaust aftertreatment regeneration.

Reference Information
Schematic Reference
* Engine Controls Schematics (Electrical Diagrams)

Connector End View Reference
* Component Connector End Views (Connector End Views By Name)

Description and Operation
* Exhaust Aftertreatment System Description (Emission Control Systems)

Electrical Information Reference
* Circuit Testing (Circuit Testing)
* Connector Repairs (Connector Repairs)
* Testing for Intermittent Conditions and Poor Connections (Testing for Intermittent Conditions and Poor Connections)
* Wiring Repairs (Wiring Repairs)

Scan Tool Reference
* Control Module References (Programming and Relearning) for scan tool information

Special Tools
* J 39021 Fuel Injector Coil and Balance Tester

Circuit/System Testing
1. Remove the indirect fuel injector outlet nozzle from the exhaust, connect a piece of hose to the indirect fuel injector outlet nozzle and place the other end into a suitable container.
2. Disconnect the harness connector at the Q57 indirect fuel injector.
3. Connect the J 39021 to the indirect fuel injector.
4. Set the amperage supply selector switch on the J 39021 to the Coil Test 2.5 amp position.
5. Engine running, verify the indirect fuel injector does not leak any fuel into the container.
^ If fuel is leaking from the outlet nozzle, replace the Q57 indirect fuel injector.
6. Command the J 39021 ON 4 times to purge the fuel lines.
7. Place the rubber hose into a graduated scale container.
8. Command the J 39021 1 time and verify at least 17 ml of fuel has flowed into the container.
^ If less than the specified amount, test the indirect fuel injector outlet nozzle and supply line for damage or restrictions. If the lines test normal, replace the Q57 indirect fuel injector.

Repair Instructions
Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.

* Indirect Fuel Injector Replacement (Indirect Fuel Injector Replacement)
* Perform the scan tool Diesel Particulate Filter (DPF) Regeneration Enable (Diesel Particulate Filter (DPF) Regeneration Enable) procedure if the scan tool DPF Soot Mass is less than 30 g. If the scan tool DPF Soot Mass is 30 g or greater, perform the Diesel Particulate Filter (DPF) Service Regeneration procedure. (Diesel Particulate Filter (DPF) Service Regeneration)