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Home >> Hummer >> 2010 >> H3 Base, Standard >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls And Fuel - 3.7L - Symptom Troubleshooting And Diagnosis >> Fuel Injector Circuit Diagnosis >> Circuit/System Testing

Circuit/System Testing

  1. Ignition OFF, disconnect the X101 fuel injector multi-way connector.
  2. Ignition ON, verify that a J 35616-200:  Test Light illuminates between the ignition circuit terminal A ECM harness side and ground.
    • If the test lamp does not illuminate, test the ignition circuit for a short to ground, or an open/high resistance. If the circuit tests normal and the ignition circuit fuse is open, test or replace the fuel injector.
  3. Ignition OFF, connect a J 35616-200:  Test Light between the ignition circuit terminal A and the control circuit ECM harness side, of the appropriate injector listed below:
    • Injector 1 terminal D
    • Injector 2 terminal E
    • Injector 3 terminal F
    • Injector 4 terminal B
    • Injector 5 terminal C
  4. Engine cranking, the test lamp should flash for each injector.
    • If the test lamp is always ON, test the appropriate control circuit for a short to ground. If the circuit tests normal, replace the ECM.
    • If the test lamp is always OFF, test the appropriate control circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the ECM.
  5. Ignition OFF, measure for 10-15 ohms on the engine harness side of X101 between the ignition circuit terminal A and the control circuit of the appropriate injector listed below:
    • Injector 1 terminal D
    • Injector 2 terminal E
    • Injector 3 terminal F
    • Injector 4 terminal B
    • Injector 5 terminal C
    • If the resistance is not within the specified range, test for a short to ground or an open/high resistance between X101 and the appropriate fuel injector harness connector. If the circuits test normal, test or replace the affected fuel injector.