Avalanche 2500 4WD V8-8.1L VIN G (2003)
Fuel Injector: Testing and Inspection
Fuel Injector Coil Test
CIRCUIT DESCRIPTION
The powertrain control module (PCM) enables the appropriate fuel injector on the intake stroke for each cylinder. A voltage is supplied directly to the
fuel injectors. The PCM 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 low, will affect 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
-
Monitoring the misfire current counters, or misfire graph, may help 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 customers concern. A fuel injector condition may only be apparent at a certain
temperature, or under certain conditions. See: Computers and Control Systems/Testing and Inspection/Component Tests and General Diagnostics
-
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 - 4
