ION L4-2.4L (2007)
Fuel Injector: Testing and Inspection
Fuel Injector Circuit Diagnosis
Fuel Injector Circuit Diagnosis
Diagnostic Fault Information
Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. See: Testing and Inspection/Initial Inspection and Diagnostic
Overview/Diagnostic System Check - Vehicle
Circuit/System Description
The control module enables the appropriate fuel injector pulse for each cylinder. Ignition voltage is supplied to the fuel injectors. The control module
controls each fuel injector by grounding the control circuit via a solid state device called a driver.
Circuit/System Testing
1. Inspect the INJECTORS fuse.
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If the fuse is open, repair the short to ground in the ignition 1 voltage circuit of the fuel injectors.
2. Remove the air cleaner outlet duct.
3. Disconnect a fuel injector.
4. With the ignition ON, engine OFF, probe the ignition 1 voltage circuit of the fuel injector with a test lamp that is connected to a good ground. The
test lamp should illuminate.
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If the test lamp does not illuminate, repair the open in the ignition 1 voltage circuit between the fuse and the splice.
5. Remove the INJECTORS fuse.
6. Measure the resistance between the INJECTORS fuse to the ignition 1 voltage circuit terminal of a fuel injector with a DMM. All wire circuit
resistance should measure less than 2 ohms.
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If the resistance is more than 2 ohms, repair the high resistance in the ignition 1 voltage circuit.
7. Connect the J 44603 into each fuel injector connector one at a time. Crank the engine.
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If the test lamp flashes for each injector, perform the Fuel Injector Diagnosis. Refer to Fuel Injector Diagnosis (w/J39021 or w/Tech 2) Fuel
Injector Diagnosis (w/CH47976). See: Computers and Control Systems/Testing and Inspection/Component Tests and General
Diagnostics/Fuel Injector Diagnosis (w/J39021 or w/Tech 2) See: Computers and Control Systems/Testing and Inspection/Component Tests
and General Diagnostics/Fuel Injector Diagnosis (With CH 47976)
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If the test lamp does not flash for each injector, test for an open or a short to voltage in the control circuit of the fuel injector, an intermittent or
poor connection at the engine control module (ECM). If the circuit tests normal, replace the control module.
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If the test lamp remains illuminated at all times for any injector circuit, test for a short to ground in the control circuit of the fuel injector. If the
circuit tests normal, replace the control module.
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure. See: Computers and Control Systems/Testing and
Inspection/Diagnostic Trouble Code Tests and Associated Procedures/Verification Tests and Procedures
Control Module References. See: Testing and Inspection/Programming and Relearning
