TrailBlazer 4WD L6-4.2L VIN S (2002)
Fuel Injector: Testing and Inspection
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. 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 engine driveability. A fuel injector control circuit DTC may not set, but a misfire may be
apparent. Fuel injector coil windings are affected by temperature. The resistance of fuel injector coil windings will increase as the temperature of the
fuel injector increases.
DIAGNOSTIC AIDS
^
Monitoring the misfire current counters, or misfire graph, may help to isolate the fuel injector that is causing the condition.
^
Operating the vehicle over a wide temperature range may help isolate the fuel injector that is causing the condition.
^
Perform the fuel injector coil test within the conditions of the customer's concern. A fuel injector condition may only be apparent at a certain
temperature, or under certain conditions.
^
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