XL-7 2WD V6-3.6L (2007)
Fuel Injector: Testing and Inspection
Fuel Injector Solenoid Coil Test
Fuel Injector Solenoid Coil Test
Diagnostic Instructions
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Perform the Diagnostic System Check See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Diagnostic System Check - Vehicle
Diagnostic Information
Vehicle Diagnostic Information prior to using this diagnostic procedure.
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Review Strategy Based Diagnosis for an overview of the diagnostic approach. See: Testing and Inspection/Initial Inspection and Diagnostic
Overview/Strategy Based Diagnosis
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Diagnostic Procedure Instructions - Vehicle Diagnostic Information provides an overview of each diagnostic category.
Circuit/System Description
The control module enables the appropriate fuel injector pulse for each cylinder. The ignition voltage is supplied directly to the fuel injectors. The
control module controls each fuel injector by grounding the control circuit via a solid state device called a driver. A fuel injector coil winding resistance
that is too high or too low will affect the engine driveability. A fuel injector control circuit DTC may not set, but a misfire may be apparent. The fuel
injector coil windings are affected by temperature. The resistance of the fuel injector coil windings will increase as the temperature of the fuel injector
increases.
Diagnostic Aids
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Monitoring the misfire current counters, or misfire graph, may help to isolate the fuel injector that is causing the condition.
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Operating the vehicle over a wide temperature range may help isolate the fuel injector that is causing the condition.
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Perform the fuel injector coil test within the conditions of the customers concern. A fuel injector condition may only be apparent at a certain
temperature, or under certain conditions.
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If the condition is intermittent, move the related harnesses and connectors, with the engine operating, while monitoring the circuit status for the
component with a scan tool. The circuit status parameter changes from OK or Indeterminate to Fault if there is a condition with the circuit or a
connection.
Component Testing
Verify the resistance of each fuel injector with one of the following methods:
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If the engine coolant temperature (ECT) sensor is between 10-32°C (50-90°F), the resistance of each fuel injector should be 11-14 ohms.
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If the resistance of any fuel injector is not 11-14 ohms, replace the fuel injector.
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If the ECT sensor is not between 10-32 °C (50-90 °F), measure and record the resistance of each fuel injector with a DMM. Subtract the lowest
resistance value from the highest resistance value. The difference between the lowest value and the highest value should be equal to or less than 3
ohms.
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If the difference is equal to or less than 3 ohms, refer to Fuel Injector Balance Test with Special Tool or Fuel Injector Balance Test with Tech
2 for further diagnosis of the fuel injectors.
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If the difference is more than 3 ohms, add all of the fuel injector resistance values to obtain a total resistance value. Divide the total resistance
value by the number of fuel injectors to obtain an average resistance value. Subtract the lowest, and the highest, individual fuel injector
resistance values from the average resistance value. Replace the fuel injector that displays the greatest resistance difference above or below the
average.
Repair Instructions
Perform the Diagnostic Repair Verification - Vehicle Diagnostic Information after completing the diagnostic procedure.
Fuel Injector Balance Test with Special Tool
