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Home >> Hummer >> 2008 >> H2 4D Utility Wagon >> Repair and Diagnosis >> External Pages >> Different car >> Section 508 (Engine Controls/Fuel - 5.3L, 6.0L, 6.2L - DTC P0420 To DTC P3449 And Diagnostic Information And Procedures) >> Diagnostic Information and Procedures >> Fuel Injector Diagnosis (CH47976) >> Component Testing

Component Testing

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Fuel Injector Coil Test 

Verify the resistance of each fuel injector:

  1. Ignition ON, verify the scan tool ECT temperature is between 10-32°C (50-90° F).
    • If not within the specified range, 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 Ω. If the difference is greater than 3 Ω, add all of the fuel injector resistance values to obtain a total resistance value. Divide the total resistance value by the number of injectors to obtain an average resistance value. Subtract the lowest individual fuel injector resistance value from the average resistance value. Subtract the average resistance value from the highest individual injector resistance value. Replace the fuel injector that displays the greatest difference above or below the average.
  2. Test for 11-14 Ω between each fuel injector.
    • If not within the specified range, replace the fuel injector.
  3. If all the injectors test OK, refer to the Active Fuel Injector Tester (AFIT) Procedure.

Active Fuel Injector Tester (AFIT) Procedure

    NOTE:
    • DO NOT perform this test if the engine coolant temperature (ECT) is above 94°C (201°F). Irregular fuel pressure readings may result due to hot soak fuel boiling.
    • Verify that adequate fuel is in the fuel tank before proceeding with this diagnostic.
  1. Verify the battery is fully charged and all accessories are OFF.
  2. Ignition OFF.
  3. Install the CH-47976  Active Fuel Injector Tester. Refer to the AFIT User Guide.
  4. Turn ON the AFIT and select the vehicle.
  5. Follow the setup screen on the AFIT.
  6. Ignition ON, perform the Injector Test. The test should run and pass all injectors.
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