Grand Prix V6-3.8L VIN 2 (2004)
Fuel Injector: Testing and Inspection
Fuel Injector Coil Test
FUEL INJECTOR COIL TEST
CIRCUIT DESCRIPTION
The control module enables the appropriate fuel injector on the intake stroke for each cylinder. Ignition voltage is supplied directly to the fuel
injectors through the powertrain power distribution relay and a fuel injector mini fuse. The control module controls each fuel injector by grounding the
control circuit via a solid state device called a driver.
DIAGNOSTIC AIDS
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A fuel injector control circuit DTC may not set, but a misfire may be apparent. Monitoring the misfire current counters, or misfire graph, may help
isolate the fuel injector that is causing the condition.
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The fuel injector coil windings are affected by temperature. The resistance of the fuel injector coil windings increases as the temperature of the
fuel injector increases. Operating the vehicle over a wide temperature range may help isolate the fuel injector that is causing the condition.
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A fuel injector coil winding resistance that is too high or too low will affect engine driveability. 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 fuel injector coil test does not isolate the condition perform the fuel injector balance test. Refer to Fuel Injector Balance Test with Special
Tool or Fuel Injector Balance Test with Tech 2. See: Computers and Control Systems/Testing and Inspection/Component Tests and General
Diagnostics See: Computers and Control Systems/Testing and Inspection/Component Tests and General Diagnostics
TEST DESCRIPTION
Steps 1-7
The numbers below refer to the step numbers on the diagnostic table.
3. This step tests each fuel injector resistance within a specific temperature range. If any of the fuel injectors display a resistance outside of the
specified value, replace the fuel injector.
4. This step determines if all of the fuel injectors are within 3 ohms of each other. If the highest resistance value is within 3 ohms of the lowest
